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User Guide Version 6.2 - RWTH Aachen University

1. name dri file P Peak 1D in txt P Peak 2D in txt dimension 1D 2D grid size cells 1x1x200 400x1x400 grid spacing 0 5um 2um interface thickness cells 5 4 boundary conditions BCs east insulation symmetric phase field west insulation symmetric BCs bottom insulation periodic top insulation periodic east insulation periodic concentration west insulation periodic field BCs bottom insulation periodic top insulation periodic solid phases 2 solid phases 2 ferrite FCC_A1 austenite deterministic placement of 1 grain round coordinates x 0 25 z 0 25 r 0 stabilisation of the grains no voronoi construction rotation angle 0 rotation angle 45 Max number of new nuclei 1 Max number of new nuclei 250 grain input further nucleation enabled seed types 1 seed position interface simultaneous nucleations automatic temperature conditions 1763 75 G 0 K cm dT dt 0 2 K s temperature MICRESS User Guide Volume IV MICRESS Examples pu latent heat NO Chapter 9 Recrystallisation files restart grains phases average fraction table concentration concentration of the reference phase average concentration per phase linearization output monitoring outputs times times output from 00 00 s to 700 s output every 50s from 00 00 s to 160 s output every 10 s linear step linear step from 160 s to 1
2. 47 917 IBeSCHIBUOTI cation hnc a Dv Du Do Eure ducet 4 9 2 Simulan Cond ONS RR 48 9 3 1 Visualisation of the results eese nnn 50 9 3 1 E 50 KETTE 3 E o A EE 5 9 3 4 He vo rt x UU MM DM MD E EUM UE 52 9 3 5 53 ere Eee RE LC CR CNET EM EEN 54 IC gui Beene neem tee 54 12 Simulauom conditions a a 55 103 Visualisation of the r Sults 0 cccccccsscssssssscsssscccsscccseecsseessesscsesessesssecscsenseseessessasesscensesenseseneasesssesens 56 14 Basic IU GoUplifig me em cd veo dde 57 Descriptio oT 57 117 Sumulatton 58 113 Visualisation of the results esee enne nnn nnn nnne nn nn nnn nnne nanus anna nia 59 TORP cuu 59 11 3 2 Eutectic ee reve wet vea rutru rece tete ie eben is 60 12 Temperature nano o anie a emer a muc Eta EI Ca a Ca SPERA 61 LAE 61 122 2 63 22 2 ce itus de cus dodo 62 1
3. LA t 0s t 0 8s t 1 6s t 2 2s Figure 9 1 The recrystallisation sequence Rex 1 phas mcr As recrystallized grains are of the same phase they can not be distinguished in the phas output Only interfaces are visible e Recrystallisation path presented by the rex output 1 interface 0 new structure recrystallized grains 1 not assigned 2 not assigned 3 initial structure non recrystallized grains t 0s t 0 8s t 1 6s t 2 2s Figure 9 2 he recrystallisation sequence Rex_1_rex mcr As recrystallized grains are of the same phase they can best be distinguished in the rex output MICRESS User Guide Volume IV MICRESS Examples mu chapter 9 Recrystalisation Chapter 9 Recrystallisation e 2 hecrystallisation path presented by the rex output 1 interface 0 new grains 1 not assigned 2 not assigned initial grains amp c amp 2 c c ce 5 c ee m c ule amp 0 c C EJ JE OS uis ud i ue E DU ci o I co Figure 9 3 The recrystallisation sequence Rex 2 phas mcr 9 3 3 ReX 3 in txt e Recrystallisation sequence presented by the orie output grain orientations t 0s t 0 15s t 0 3s t 0 45s t 0 55s t 0 6s Figure 6 The recrystallisation path Rex_3_orie mcr Different grains may also be distinguished by the
4. User Guide Version 6 2 Volume IV Examples Resolution of partial differential equations is more about art than science Apocryphal quotation from Numerical Recipes in Fortran 2 2 4 except for large values of 2 Anonymous 2 Douglas Adams Edited by MICRESS group Contents CREER R 1 1 introduction nananana nannan annann nanana 1 IRA Rt 3 3 Examples Overview nenene ananena 5 CILE em 10 PSC n ee 10 4 2 STESSO 11 4 3 Visualisation of the results 4 1 eese nennen nnn nnnm nnnm nnnn nnn sa nnn nannan 12 9 ec 14 MIU ee U 14 5 2 Simulation conditiOns eese nennen nnn nnne nnns 15 5 3 Visualisation of the results 1 lees nnnm nnnm nanenane 16 5 3 1 PUET aiee 16 5 3 2 Solidification sequence presented by the 17 5 3 3 RR 18 6 Y 21 s aa Roa Nn Dc Foral eU uu 21 b2 Sim lation COMM S Ent rv 24 63 Visua
5. 1 107 cm s water p 19 1 10 cm s Table 23 Example Delta Gamma simulation conditions parameters 15 3 Results In figure 15 2 the flow patterns caused by a cylindrical object are compared for two different Reynolds numbers For low Reynolds numbers a very simple stationary pattern occurs at higher Reynolds numbers eddies will form behind the obstacle and at even higher Reynolds numbers periodically changing patterns like a Karman vortex street may evolve after some simulation time MICRESS User Guide Volume IV MICRESS Examples pu gt gt gt 2 gt 2 2 22 2 2 22222 gt gt gt 2 2 2 222 2 2 gt gt gt gt gt gt gt 2 gt 2 2 2 2 gt gt gt gt gt gt ee ee Nan gt gt 2222 2 2 22222222A Aaa 2 gt 322222222222 2AA A AAA A AAA a 3445 322222222922 J I 2 gt PPP PMMA AA 22 A b gt gt 7 77 gt 7777777 7 o 7 s OQ 33250505637 09g A 4 4 5555555555 5524 5555555555 gt 5 gt gt gt gt gt gt gt gt gt gt gt gt gt 3 4 gt gt gt gt 3 44 gt gt gt gt gt gt 3 gt ee oe 0 TN PPP PP PP FPF FFF gt gt 2222222233 333333335323 9
6. Le Co ij i op Lu on am LL i LL n e ca in Figure 10 1 The von Mises stress field Stress vM mcr e Normal stresses in x y and z direction presented by the cV outputs t 0s Stress sxxCV mcr t 0s Stress sxzCV mcr t 0s Stress szzCV mcr Figure 7 The normal stress distributions in different directions MICRESS User Guide Volume IV MICRESS Examples 6 Chapter 11 Basic TQ Coupling 11 Basic TQ Coupling 11 1 Description The two examples Ripening and Eutectic illustrate the basics of the Thermo Calc coupling via its TQ interface Here phase transformations are simulated in an aluminium silver alloy The first model is isothermal and shows the effect of curvature The second one is similar and adds heat extraction and simulation of latent heat release with growth of a primary and a secondary phase as well as solid solid interaction after the complete solidification im Ripening in txt name TQ Eutectic in txt alloy system Ag Al Seta Bin GES5 32 composition 68 at Al transition phase transformation Table 16 Example TQ Coupling details MICRESS User Guide Volume IV MICRESS Examples mu lt Chapter 11 Basic TQ Coupling 11 2 Simulation conditions name dri fi
7. G 0 K cm dT dt 10 K s temperatur e conditions 1521095 G 0 K cm latent heat NO output files restart grains phases average fraction table interface driving force grain time concentration reference phase concentration monitoring outputs normal stress von Mieses stress output displaceme nt data times times times from 01 0 s to 6 s output every 1 0s linear step output at 00 25 and 01 00 s output at 5 from 06 0 s to 10 s output every 2 05 linear step from 01 00 s to 10 s output every 0 5s 10 and 15s from 10 0 s to 30 s output every 5 05 linear step linear step from 30 0 s to 100 s output every 10 5 linear step from 10 00 s to 35 s output every 1 s from 100 s to 300 s output every 25 5 linear step linear step concentrati special features concentration coupling coupling NO 1d far field diffusion approximation thermodyna bibi thermodynamic coupling enabled no thermo thermo thermo dynamic dynamic dynamic coupling uin coupling FECMn Gesb coupling database database linearTQ global global database global NO moving frame MICRESS User Guide Volume IV MICRESS Examples pu Table 7 GammaAlpha Examples Overview of simulation conditions parameters chapter 6 Gamma Alpha Chapter 6 Gamma Alpha 6 3 Visualisation of the results 6 3 1 Gamma Alpha dri and Gamm
8. and Grain Growth Solute Drag shows how MICRESS can be used without coupling to external fields like temperature or concentration i e using only the curvature as a driving force for the transformation Respective curvature based coarsening is inherent to phase field models These examples show how to read in initial microstructures The Grain Growth example displays pure grain growth whereas the other examples draw on specific models hindering grain boundary motion like e g the particle pinning the solute drag and KTH solute drag models respectively In addition grain growth with non linear temperature profiles is modeled in the Grain Growth Profiles example he example Grain Growth Solute Drag dG in txt IS the same as Grain Growth Solute Drag in txt apart from the mobility which is not constant but dependent on the driving force Grain Growth in txt Grain Growth Particle Pinning in txt name dri file Grain Growth Profiles in txt Grain Growth Solute Drag 96 in txt Grain Growth Solute Drag in txt alloy system not specified e g steel composition not specified e g austenite modelled phenomenon growth with without pinning Table 8 Examples Grain Growth details MICRESS User Guide Volume IV MICRESS Examples Pu Chapter 7 Grain Growth 7 2 Simulat
9. so melt flow can pass tangentially through the phase field interface but is slowed down MICRESS User Guide Volume IV MICRESS Examples 12728 For the dendritic structure the simulation yields a steady velocity field with an average velocity v 2 8 10 m s The average pressure gradient given in the input equals the pressure difference over the length in x direction g Ap L 1 Pa 199 um 5 10 kg m s The dynamic viscosity from the material data section for fluid flow is given by the kinematic viscosity ant the density u 7 10 kg ms From these values the permeability results as V k 39 107 m The value for the liquid fraction of the simulation domain is provided in the tabulated fractions as 84 Figure 15 3 Flow through a dendritic structure MICRESS User Guide Volume IV MICRESS Examples pu
10. 38 5 5 5 5 5882682686 gt gt gt 2 2 2 3333 gt 33 3 33 gt gt gt gt gt gt gt gt SE gt gt gt gt 2 2 2 2 2 2 2 gt gt gt gt gt gt 2 gt 2 2 22 2 2 2222 a a Jon a St ee 3 I YM SS 3 3 3 35 3 3 3 95 3 39 3 AAA A D gt A AA AY jj uU Vso ZAAAAAAAAZ A y v SSA AA AAP _ 7777722 gt FRR RR EC ee f f l l Se Ss ABBA reer ee ee ued SV BSN lt o 974959 _ gt gt N gt gt 5222 222 a E ee ee ee SSS 5 5 nnn gt a gt 5 2 Flow around a cylinder for Re 1 6 10 top and Re 100 bottom The white circle indicates the grain geometry from the driving file In the Karman example the grid distance Is quite large so the interaction of melt flow with the phase field interface can be seen The solid fraction has a braking effect on the fluid flow
11. A is fixed If selection of A is the goal a different setup of dendrites growing along temperature gradient should be chosen In the course of solidification different elements are segregated to the interdendritic liquid leading to precipitation of y phase before the end of solidification Precipitation of this phase from the solid has not been included in this simulation setup Due to the high number of dissolved elements updating thermodynamic data is very slow For that reason a global relinearisation scheme keyword global has been chosen as relinearisation scheme which uses only one set of linearization data for the whole interface of e g a particle with liquid This is a reasonable assumption as the chemical composition of liquid around this particle is quite homogeneous and no temperature gradient is present But for the fcc liquid interface this is no longer true when the liquid phase splits up into smaller regions which may have different composition Therefore the option globalF which is new in MICRESS 6 2 has been used With this relinearisation mode fragmentation of the interface into disconnected regions is detected and for each fragment an individual set of linearization parameters is assigned Note that this example further uses temperature dependent interface mobility values as well as diffusion coefficients which are read from ascii files during simulation This is not so much meant for improving physical correct
12. User Guide Volume IV MICRESS Examples mu C Chapter 12 Temperature e Growth of a spherical particle as taken from the phas output t 0s t 9 9999997E x 104 6 t 4 9999999E x 104 5 u 4 i M 4 f 1 t 9 9999997E x 10 5s t 1 9999999E x 10 4s t 1 0E x 10 3 Figure 12 2 lemperature phas mcr MICRESS User Guide Volume IV MICRESS Examples mu Chapter 13 Ni based Alloy 13 Ni based Alloy 13 1 Description The example CMSXA dri illustrates the design of the input file for directional solidification of a complex technical alloy The challenge here is not only the high number of elements but also the high composition level and the proximity of composition to the spinoidal decomposition region avoid apparent demixing connected with the multi binary extrapolation scheme the diagonal elements of the partition matrix are used instead for redistribution as invoked by the interaction keyword without further parameters A further optimisation would be possible here by defining suitable ternary subsystems for more exact extrapolation As initial situation 14 small grains are positioned such as to reproduce two regular grids which are connected by a grain boundary The orientations of the cubic fcc grains has been chosen according to the typical stacking Inside grains when looking at isothermal sections in directionally solidified samples Thus the primary dendrite arm distance
13. cc cc cc dimension 2D grid size cells 400x1x400 500x1x500 400x1x400 500x1x300 500x1x1000 grid spacing 0 25um 0 5um 2E 02um 0 5um interface thickness 5 A cells boundary conditions BCs east insulation Insulation periodic insulation periodic phase field west insulation insulation periodic insulation periodic BCs bottom insulation insulation insulation insulation insulation top insulation insulation insulation insulation insulation solid phases 1 solid phase different stored energy assigned to different grains random integer random integer deterministic for randomization deterministic for randomization 13 two types of 4 types of grains grains type 1 22 new grains type 1 5 type 2 3 new grains round 6 new grains round 100 type 2 30 elliptic 5 type 3 15 type 4 5 elliptic stabilisation Voronoi construction qr er nucleation further nucleation further nucleation further nucleation further nucleation YES NO YES YES NO grain input phase interaction pure mobility constant recrystallisation phase 1 anisotropic cubic symmetry misorientation 3 types of seeds 2 types of seeds 2 types of seeds position of the position of the seed position seeds interface seeds interface interface region triple bulk seed region seed stabilisation undercooling undercooling maximum number nucleation model nucleation model of simultaneous applied maximum applied maximum nucleations 5 num
14. local concentration is lowered due to the oncoming fresh not Si enriched melt Periodic boundary conditions for the concentration field were employed in the z direction to keep the total Si concentration in the simulation domain constant Material data for fluid flow is provided by literature Density of liquid AISi7 p 2 7 g cm and the dynamic viscosity at solidification temperatures 1 10 kg ms equates to a kinematic viscosity of 3 7 10 5 14 2 Simulation conditions name dri file Dendrite AlSi 3D dri Dendrite AlSi 3D flow dri dimension 3D grid size 100x100x100 cells 80x80x200 cells grid spacing interface 3 5 cells MICRESS User Guide Volume IV MICRESS Examples mu Chapter 14 oymmetric at west and south boundaries symmetric at west south and bottom boundaries insulation at east and north boundaries boundary conditions insulation at east north and top boundaries At top and bottom periodic concentration and phase field fixed flow of 1mm s in z direction solid phase Fec Al One seed at origin 1 1 1 center of the One seed in the middle of the z axis 1 1 200 seed input symmetric cell l In lattice orientation In lattice orientation files fraction phase 1 concentration 1 Si in phase files fraction phase 1 concentration 1 Si in output 0 liquid log and fraction tables phase 0 liquid log and fractio
15. model for pearlite The main features of the individual models in the group Gamma Alpha are reviewed in the next section a Gamma Alpha dri txt Gamma Alpha dri txt Gamma Alpha PARA dri txt Gamma_Alpha_PARATQ_dri txt name dri file b Gamma_Alpha_Stress_dri txt c GammaAlphaCementite_LinTQ_dri txt GammaAlphaCementiteTQ_dri txt GammaAlphaPearlite_dri txt alloy system Fe C Mn FeCMn Ges5 0 1 wt C 1 5 wt Mn composition b 0 103 wt C 0 49 wt Mn c 0 25 wt C 0 174 wt Mn Table 6 Overview damma alpha examples transition solid phase transition MICRESS User Guide Volume IV MICRESS Examples Pu Chapter 6 Gamma Alpha Group a in Table 6 demonstrates how to use MICRESS for simulation of solid state transformations like the aloha to gamma transition Characteristic for simulation of solid state transformations is the necessity to define an initial microstructure which is typically not needed in case of solidification In this case 9 initial grains of ferrite are positioned with user defined center coordinates and radii Voronoi construction is used to obtain typical grain structure without overlapping or holes The specific input data can either be chosen manually for small numbers of grains or taken from specific tools like Random Grid Alternatives for definition of initial grain structures are random generation or reading from experimental microstructures or prior MI
16. periodic periodic periodic periodic periodic periodic periodic periodic West periodic periodic periodic periodic periodic periodic periodic periodic phase North insulation field BCs south insulation bottom periodic periodic periodic periodic periodic periodic periodic periodic top periodic periodic periodic periodic periodic periodic periodic periodic East periodic periodic periodic periodic periodic periodic periodic periodic West periodic periodic periodic periodic periodic periodic periodic periodic North insulation tion field BCs south insulation bottom periodic periodic periodic periodic periodic periodic periodic periodic top periodic periodic periodic periodic periodic periodic periodic periodic solid phases 2 solid phases y a 3 solid phases y a cementite deterministic random 12 grains of placement of 9 grains of a phase round 8 grains of one type of grains round ol grain input round stabilisation of the grains Voronoi construction further nucleation enabled seed seed types 3 seed types types 3 MICRESS User Guide Volume IV MICRESS Examples Chapter 6 Gamma Alpha seed positions triple interface bulk seed undercooling nucleation model applied simultaneous nucleation automatic temperature conditions 1 1023 G 0 K cm dT dt 0 K s seed positions triple interface temperature conditions T 1030
17. there with steady restart or frozen phase field when adjusting convergence parameters MICRESS User Guide Volume IV MICRESS Examples pu lt Chapter 15 152 Simulation conditions name dri file Flow Cylinder Laminar dri Flow Cylinder Karman dri Flow Permeability dri dimension 2D 3D grid size 200x100 cells 200 75 cells 199x100x100 grid spacing 0 5 2um Tum interface 9 cells 2 5 cells flow boundary conditions Insulation at top and bottom in outflow with fixed pressure east Insulation at top and bottom Fixed velocity inflow west fixed symmetry at top bottom north and south periodic conditions with and west pressure outflow east pressure gradient for east west One circular grain Radius 10 um in One circular grain Radius 10 um Structure from file vtk file with the middle of the domain closer to the inflow cell values marking solid with 1 output files solid fraction flow velocities and pressures solid fraction flow velocities special features combined solver fixed timestepping piso solver cfl timestepping combined solver steady start vtk output Average v 1 6 10 5 result 1 10 um s boundary condition 2 8 10 um s result Reynolds number 1 6 107 100 2 8 10 100 domain width Material flow parameters Density 19 viscosity
18. 23 Visualisation of the results esee errem nnn nnn nn nnn nn nana sanas anna naa 63 13 dp 65 131 c 65 132 66 133 Visualisation of the results 4 eese nnnm nnn nnnm nnn innu nn nnn sanas anna nus 67 14 CBenUHfes bi a a ee nu re Gi E ru iid 69 JBeScFIDIOIL hee aad taie a Du e nana nanan 69 14 2 Simulation conditions sees nnne return nitens te transeo anas 69 14 3 Tweaking performance acest 70 MA SUES Rr Ma ND ID A eR I E P 71 19 JI 13 men Ueto fC eerie te ae odio noa Moab MEUM UM M d EE 73 TEAS Laminar flow around a cylinder osse acea ettet cuo 73 15 1 2 Formation of a Karman vortex street 79 Doleo PONES 74 152 Simulation conditlolls Xr ppc cci c dh un e va o b 15 ILS MB llc 15 Chapter 1 Introduction 1 Introduction The software MICRESS MICRostructure Evolution Simulation Software is developed for time and space resolved numerical simulations of solidification grain growth recrystallisation or solid state transformations in metallic alloys MICRESS covers phase evolution solutal and thermal diffusion and transformation strain in the solid state It enables the calculation of microstructure formation in time and space by solving the free boundary p
19. 70 s output every 2 5 s linear step from 700 s to 2500 s output every 100 s from 170 s to 200 s output every 10 s linear step linear step from 200 s to 600 s output every 50 s linear step from 600 s to 3000 s output every 100 s linear step concentration coupling NO 1d far field diffusion approximation special features thermodynamic coupling enabled Fe C Mn 51 5 datafile NO moving frame Table 11 Example Phosphorus Peak field parameters MICRESS User Guide Volume IV MICRESS Examples pu chapter 9 Recrystalisation Chapter 9 Recrystallisation 8 3 Visualisation of the results 8 3 1 P Peak 1D in txt P Peak 10 P Peak 1D conc2 P Peak 1D conc3 P Peak 1D 4 c El c i c Figure 4 The 1D concentration field Peak 10 conc1 mcr to P Peak 10 conc4 mcr 1 C 2 Mn 3 P and 4 Si for t 2000s MICRESS User Guide Volume IV MICRESS Examples C Chapter 9 Recrystallisation 8 3 2 P Peak 2D in txt e Solidification sequence presented by the phas output 1 interface 0 liquid 1 2 ferrite 2 austenite CN t 160 0s t 162 0015s t 166 638s L 1 M b i 4 x 1 t 170 0s t 200 0s t 500 0s t 3000 0s Figure 5 The solidification path Peak 2D phas mcr MICRESS User Guide Volume IV MICRESS Examples pu cha
20. CRESS simulations Transformation is calculated at a constant temperature of 1023K 750 C where the alpha fcc phase is thermodynamically stable But during the phase transformation the dissolved elements C and Mn are redistributed reducing the driving force for transformation While C is a fast diffusor and can move away from the interface Mn diffuses too slow in the time scale of the transformation and thus must be overrun nple or trapped para paratq This fact that the diffusion profiles of Mn cannot be spatially resolved makes it necessary to use specific models for solute redistribution which avoid artefacts of the standard redistribution model In these examples the conditions are chosen such that the different redistribution modes nple and para paratq are leading to substantially different transformation rates because in case of nple the pile up of the element Mn in front of the moving interface is taken into account for calculation of the driving force while in case of para or para tq It isn t The purpose of the 4 different versions of Gamma Alpha is to demonstrate on one hand the differences when using linearised phase diagram data and fix Arrhenius type diffusion coefficients versus thermodynamic and diffusion databases and on the other hand the redistribution models versus para paratq For the first type of comparison Gamma Alpha dri vs Gamma Alpha dri and Gamma Alpha PARA dri vs Gamma Alpha
21. SS Examples mu Chapter 11 Basic TQ Coupling 11 3 Visualisation of the results 11 3 1 TO Ripening in txt ripening sequence presented by the korn output grain numbers t 0s t 0 5119116s 1 qa t 0 7239454 t 1 0s Figure 11 1 TQ_Ripening_korn mcr MICRESS User Guide Volume IV MICRESS Examples mu Chapter 11 Basic TQ Coupling 11 3 2 TO Eutectic in txt e phase transition path presented by the korn output 3 ua C C C C Ww 4 qu C C C C s C e C t 0s isis u t 0 34s t 0 55s Figure 11 2 korn mcr MICRESS User Guide Volume IV MICRESS Examples mu 6 Chapter 12 Temperature 12 Iemperature 12 1 Description The example Temperature dri illustrates the use of coupling to a temperature field for the case of a sphere of a pure substance growing into an undercooled liquid name dri file Temperature in txt alloy system arbitrary model material with Tm 1000K composition pure phase phenomenon Solidification of pure substance Table 18 Example Temperature details MICRESS User Guide Volume IV MICRESS Examples mu Chapter 12 Temperature 12 2 Simulation conditions name dri file Temperature in txt dimension 2D grid size 75x1x75 cells grid spacing lum interface thickness 7 cells boundary co
22. a Alpha dri Gamma Alpha phas mcr Gamma Alpha phas mcr t 0s MICRESS User Guide Volume IV MICRESS Examples chapter 6 Gamma Alpha Chapter 6 Gamma Alpha C composition after 50 s Figure 6 1 The phase transition sequence for the driving files Gamma Alpha dri txt and Gamma Alpha TQ dri txt Gamma Alpha phas mcr Gamma Alpha PARATO phas mcr MICRESS User Guide Volume IV MICRESS Examples pu chapter 6 Gamma Alpha Chapter 6 t 300s Figure 6 2 The phase transition sequence for the driving files Gamma Alpha TQ dri txt and Gamma Alpha dri txt MICRESS User Guide Volume IV MICRESS Examples pu 6 Chapter 6 Gamma Alpha 6 3 2 Cementite LinTO dri and Cementite TO dri Phase transition path presented by the phas output Note Same results but different colour codes used for the output 1 redinterface 0 mot assig 2 alpha 3 eementite Gamma Alpha Cementite LinTQ phas mcr m t 0s t 6 5s t 13s t 35s Figure 6 3 The phase transition path GammaAlpha_Cementite_LinTQ_dri and GammaAlpha_Cementitelq_dri MICRESS User Guide Volume IV MICRESS Examples chapter 6 Gamma Alpha Chapter 6 Gamma Alpha e Concentration Gamma_Alpha_Cementite_LinTQ_in txt Carbon Gamma Alpha in txt Carbon Concentration Co
23. alculation domains e arbitrary number of components phases and grains e solid solid and solid liquid interaction e anisotropy of grain boundaries mobility and energy MICRESS supports e coupling to thermodynamic database the TO interface of Thermo Calc In the present MICRESS User Guide Part IV MICRESS Examples you will find e anoverview of available MICRESS examples e a short description of the different examples their scope and the respective simulation conditions parameters e some visualized results for each example Major scope of this manual is to provide a quick overview over the different examples and different MICRESS features used to run them without the need of visualizing the results with MICRESS or stepping deeper into the respective driving files A description of the phase field phenomenology and theoretical background can be found in MICRESS Vol 0 MICRESS Phenomenology MICRESS Vol I Installing MICRESS provides information about the installation of the software and explains how to verify successful installation with the help of simple examples MICRESS Vol II Running MICRESS offers an overview of the input file structure as well as theoretical and practical information on metallurgical processes numerical modelling using the phase field model and troubleshooting when starting a simulation It provides useful hints on how to build the input file according to the process to be simulated MICRESS Vo
24. ber of number of MICRESS User Guide Volume IV MICRESS Examples pu Chapter 9 Recrystallisation simultaneous nucleations 10 simultaneous nucleations 25 temperature conditions T 1000 G 0 K cm dT dt 0 K s temperature conditions 121000 G 0 K cm dT dt 1 K s latent heat NO output files phases interface recrystallisation recrystallized fraction output orientation files orientation files grain number output files recrystallisation miller indices orientation linear step output output at 0 2 and 2 2 s linear step output output at 0 05 and 0 6 5 output from 0 to 10s every 0 5 s output from 10 s 15 s every 15 output from 10 s to 30 s every 5s output from 20 to 270 s every 30 s linear step output from 0 to 5s every 0 5 s output from 5 s to 10 s every 1 output from 10 s to 20 s every 2 s output from 20 to 30 s every 50 s linear step special features phase field coupling no thermodynamic coupling NO moving frame MICRESS User Guide Volume IV MICRESS Examples pu Table 13 Example Recrystallisation simulation conditions Chapter 9 Recrystallisation 93 1 Visualisation of the results 93 1 1 in txt e Recrystallisation path presented by the phas output 1 interface 0 not assigned 1 solid T ae A7 d N
25. complexity of the MICRESS software which has already successfully been applied to technical alloy systems with more than 14 different thermodynamic phases but rather demonstrate its basic features on the basis of simple examples The following tables give an overview of the features covered in the examples There are basically two examples categories The first table 1 comprises solid state transformation examples whereas the second table 2 is dedicated to solidification examples Example E E gt e ME ci 5 6 oic D a c M d MICRESS User Guide Volume IV MICRESS Examples chapter Examples Overview Chapter 3 Examples Overview transformation id state id state solid state id state id state SO SO SO SO recrystallisation concentration coupling temperature coupling deb UE ww LL E ese J seed density seed undercon X X X X ing recrystalli sation time step initial E microstructure nucleation model MICRESS User Guide Volume IV MICRESS Examples chapter Examples Overview Chapter 3 Examples Overview thermodynamic databases d TE tion 1d far field EN 1d field for temperatur e coupling moving frame particle pinning redistributi on anisotropy model boundary conditions phase interaction modes c
26. dded to the collection in order to demonstrate simulation of the directional solidification of a complex 10 component alloy in the isothermal cross section including a grain boundary Main features are the formation of primary dendrites and the interdendritic precipitation of y phase several advanced features of MICRESS 6 2 are used in this example Examples for flow solver usage have been provided and are described in the sections Dendrites and Flow Dendrites consists of two examples one without and one with melt flow simulating growth of a three dimensional equiaxed dendrite in AlSi7 with concentration coupling The Flow examples simulate fluid flow for a static phase field The Flow Cylinder examples show how the flow pattern around a cylinder differs for different Reynolds numbers The Flow Permeability example shows how to read in a structure and simulate fluid flow to determine its permeability MICRESS User Guide Volume IV MICRESS Examples PU Chapter 2 What s new MICRESS User Guide Volume IV MICRESS Examples P AC chapter Examples Overview Chapter 3 Examples Overview 3 Examples Overview MICRESS examples are located in the MICRESS installation directory or can be downloaded from the web www micress de They do not cover the entire range of applications of the software but treat some typical cases and can be used as starting points for other purposes They also do not exploit the full
27. ded size of Thermo Calc workspace gt thermodynamic coupling YES gt relinearisation modes global and globalF Table 21 lemperature Example simulation conditions 13 3 Visualisation of the results t 10s t 30s Tungsten concentration for different times F m MICRESS User Guide Volume IV MICRESS Examples 6 Chapter 13 Ni based Alloy t 130s t 400s NM Figure 13 1 Concentration field of W after different times MICRESS User Guide Volume IV MICRESS Examples mu Chapter 14 14 Dendrites 141 Description In the Dendrite examples dendritic solidification of AlSi7 alloy is simulated in three dimensions The thermodynamics for AlSi7 liquid and fcc Al phase is described as a linearized phase diagram One objective is to demonstrate the effects of fluid flow on dendritic growth This is done by simulating the growth of a dendrite in a forced fluid flow of 1mm s MICRESS currently does not include movement of solid phases meaning that effects of pressure or frictional forces on solid phases are neglected so the dendrite is immobile and not transported with the fluid flow The melt flow affects the local concentration by advective transport This leads to higher Si concentrations downwind of the solidifying dendrite leading to slower growth in direction of the melt flow In contrast the dendrite grows faster against the flow direction where the
28. dri it is demonstrated how input is specified When comparing the simulation results it turns out that there are substantial differences The reason here is that the different redistribution modes nple and lead to strongly different local tie lines which cannot be reasonably approximated by a single linearized description The second type of comparison Gamma Alpha dri vs Gamma Alpha PARA dri and Gamma Alpha dri vs Gamma Alpha PARATO dri shows strong differences in the transformation kinetics due to the different redistribution behaviour of Mn It should be noted that the numerical and physical parameters used in these examples are not necessarily correct or validated by literature The user who intends to build up own simulations based on these examples takes the full responsibility for choosing reasonable values Group b in Table 6 consists of a single example and demonstrates how to include elastic stress in the simulation of the gamma alpha transformation Note that in this case stress is calculated only for the output time steps The contributions to the driving force are neglected here MICRESS User Guide Volume IV MICRESS Examples pu Chapter 6 Gamma Alpha Group c in Table 6 includes cementite as a further solid phase into the simulation The spatial resolution is adapted for the gamma alpha reaction and thus too low for resolving individual pearlite lamellae Two different strategies are compared
29. eations temperature conditions 1 915 G temperature conditions temperature conditions 0 K cm T 950K T 912 G 200 K cm dT dt 10 K s Heat flow J s cm 50 000 Temp field from file latent heat NO latent heat 3D enabled files restart grains phases fraction average fraction table interface driving force mobility curvature interface velocity grain time concentration reference phase concentration orientation orientation time linearization monitoring outputs relinearisation Dot times automatic output from 0 s to 2 s times fixed output at 0 03 s output every 0 1 s linear step from 0 03 s to 0 05 s output every 0 003 s linear step from 0 05 s to 0 4 s output every 0 01 s linear step special features MICRESS User Guide Volume IV MICRESS Examples mu concentration coupling 1d far field diffusion approximation 30 cells distance from the front 60 NO 1d far field diffusion approximation thermodynamic coupling GES file Al Cu GES5 boundary 60 um moving frame distance from the upper NO moving frame Table 5 Overview of Aluminum Copper example simulation conditions 6 Chapter 5 Aluminium Copper 5 3 Visualisation of the results 5 3 1 Concentration AlCu_dri txt Figure 5 1 Concentration conc Cu at t 2s for driving file AlCu_dri txt e AlCu_Equiaxed_dri txt Figure 5 2 Concentration conc1 Cu at t 2s for driving f
30. endrite in the melt flow grows faster against and perpendicular to the flow since the Si enriched melt is carried away In the solute enriched region in flow direction the dendrite grows slowest Without melt flow the dendrite exhibits only cubic anisotropy and the Silicon M concentration disperses slower MICRESS User Guide Volume IV MICRESS Examples pu Chapter 15 15 How 15 1 Description These examples demonstrate usage of the flow solver To simplify matters only phase field coupling is switched on and the phase field is made static by reducing the mobility The phase field solver is only used at the beginning of the simulation to generate a phase field profile from the sharp interface The Cylinder examples demonstrate some features of the flow solver at the case of fluid flow around a static cylinder The Permeability example shows the practical application of calculating the permeability for a given dendritic structure 15 1 1 Laminar flow around a cylinder In this case conditions were chosen so that a stationary laminar flow around a cylinder results The fluid flow is driven by the difference between the fixed pressures at in and outflow Under these conditions flow is accelerated until frictional forces compensate the driving forces Frictionless or gradient boundary conditions at the top and bottom walls should be avoided here since they would lead to unphysical situations with unending accelerati
31. every 10 s linear step output every 0 02 s from 250 00 s to 1000 s output every 50 s linear step linear step from 0 4 s to 1 s output every 0 05 s linear step phase field coupling no thermodynamic coupling microstructure read in from file Grain Growth Microstructure txt NO moving frame special features driving force temperature dependent mobility dependent mobility gt temperature trend read in from file Table 9 Example Grain Growth field parameters MICRESS User Guide Volume IV MICRESS Examples pu chapter 7 GrimGrow Chapter 7 Grain Growth 13 Visualisation of the results 7 3 1 Pure grain growth and grain growth with particle pinning and solute drag Grain growth sequence presented by the korn output each grain has a different colour Grain Growth in txt Grain Growth Particle Pinning Grain Growth Solute Drag in txt 1 05 1 05 0 1 t 500s t 500s t 500s E 4 E C 1 10005 t 1000s t 1000s Figure 7 1 Grain growth sequence presented by the korn output each grain has a different colour MICRESS User Guide Volume IV MICRESS Examples chapter 7 7 3 2 Grain Growth Solute Drag dG in txt t 0s 5 N t 1000s Figure 1 grain growth sequence with driving force dependent mobility Grain Growth Solute Drag 90 korn txt MICRESS User Guide Volu
32. hanges when the flow pattern changes so the convergence criteria must be adjusted to work for the vortex pattern 15 1 3 Permeability example his is a demonstration of vtk DataFile Version 3 0 vtk DataFile Version 3 0 u vtk output vtk output evaluating the permeability for a ASCII T DATASET STRUCTURED POINTS DATASET STRUCTURED POINTS 3D structure read in trom an ascii DIMENSIONS 199 100 100 DIMENSIONS 200 101 101 vtk file This file contains after a SPACING 1 1 1 SPACING 1 1 1 i ORIGIN 0 0 0 ORIGIN 0 0 0 header describing the contents _ 1990000 CELL DATA 1990000 SCALARS solid double SCALARS korn float sellos of Bes and 260968 LOOKUP TABLE default LOOKUP TABLE default marking cells as grain 1 solid or 000000000 000000000 grain 0 liquid Such files can be produced with DP_MICRESS Figure 15 1 Changes to present POINT data as CELL data Another way is to produce legacy vtk output from ParaView under Data gt Save Data In this case it may be necessary to apply an image resampling filter first with the X Y and Z cell count to generate data on a structured grid Since MICRESS expects cell centred coordinates it may be necessary to edit the header as shown in Figure 15 1 After the grains are read in as grain structure the profile is adjusted to generate a smooth profile from the sharp interface but blocky grain structure The solid fraction achieved in this way should be chec
33. how pearlite is represented In GammaAlphaCementite a high number of individual cementite particles are nucleated resembling a phase mixture with consistent phase fractions and compositions but incorrect microstructure On the other hand GammaAlphaPearlite uses a diffuse phase model which represents pearlite as a continuous phase mixture GammaAlphaCementite LinTQ dri is added for demonstrating how to proceed if a certain phase cementite in this case is not contained in the thermodynamic database Here only the interaction between gamma and alpha is simulated using the database while the interactions of these two phases with cementite are defined by linearized phase diagrams in this case using the linTQ format MICRESS User Guide Volume IV MICRESS Examples EX Chapter 6 Gamma Alpha 62 Simulation conditions E 5 C X e 5 Fas 5 p 2 lt z 5 2 o 9 oc oc E Z lt lt i C C m E E E E lt lt lt lt lt lt lt lt lt lt lt lt E z c5 c5 c5 c5 c5 c5 c5 dimension 2D 3D grid size cells 250x1x250 50x20x50 grid spacing 0 25um 0 5um interface thickness 35 A cells boundary conditions BCs East
34. ification sequence at 1 12 5 25 27 5 and 30 secs 1 5 1 9 1 5 0 5 0 5 0 5 0 5 0 5 0 5 1 5 1 5 0 5 E 0 5 1 05 0 5 A preset 6 ferrite grain lower left corner of upper left picture grows dendritically in a temperature gradient bottom cooling A y austenite grain nucleates lower left picture and the peritectic reaction transformation proceeds lower row e Concentration of carbon C and Manganese MICRESS User Guide Volume IV MICRESS Examples mu chapter Delta Gamma Chapter 4 Delta Gamma Figure 4 3 The concentrations fields for C Delta Gamma conc1 and Mn Delta Gamma conc2 for t 35s MICRESS User Guide Volume IV MICRESS Examples pu 6 Chapter 5 Aluminium Copper 5 Aluminium Copper 5 1 Description The three examples Aluminium Copper show the 2D solidification of a binary aluminium copper alloy The AlCu example corresponds to a directional solidification situation whereas AlCu_Equiaxed_dri and AlCu_Temp1d_dri describe equiaxed solidification All three examples are concentration coupled with Thermo Calc coupling AlCu Equiaxed dri and AlCu Tempid provide an example of the use of the seed density nucleation model Additionally AlCu_Temp1d_dri demonstrates the read in of data files for temperature dependent mobilities and latent heat as well as the use of the far field approximation f
35. ile AlCu_Equiaxed_dri txt MICRESS User Guide Volume IV MICRESS Examples pu C Chapter 5 Aluminium Copper 5 3 2 Solidification sequence presented by the phas output e AlCu_dri txt 1 interface 0 liquid 1 phase 1 05 0 1 t 0 5s t 1 0s t 1 5s t 2 0s Figure 5 3 The solidification path AlCu_dri txt Example AlCu_phas MICRESS User Guide Volume IV MICRESS Examples mu C Chapter 5 Aluminium Copper e Equiaxed dri txt 1 interface 0 liquid 1 fcc_A1 phase t 0 1s t 1 0s 1 2 5 Figure 5 4 The solidification path dri txt Example AlCu_Equiaxed_phas 533 AlCu_Temptd_dri txt e Solidification sequence presented by the phas output phase numbers 1 interface 0 liquid 1 phase 2 ALCU_THETA MICRESS User Guide Volume IV MICRESS Examples 8 83 chapter 5 Aluminium Copper Chapter 5 t 0s t 9 0000004Ex10 2s 1 0 18 1 0 38 t 0 4s Figure 5 5 The solidification sequence for the driving file AlCu_Temp1d_dri txt MICRESS User Guide Volume IV MICRESS Examples mu 6 Chapter 5 Aluminium Copper e Concentration AlCu_Temp1d_conc1 mer Figure 5 6 Concentration of copper after 0 4 seconds for driving file AlCu_Temp1d_dri txt MICRESS User Guide Volume IV MICRESS Example
36. ion conditions E 7 x D o gt S 2 2 S E 5 g 2 e E 5 5 a p c c5 c c c E E c co Co iS C dimension 2D grid size cells 400x1x320 100x1x500 grid spacing 1 5um interface thickness 5 cells boundary conditions BCs phase field East periodic periodic periodic periodic periodic BCs West periodic periodic periodic periodic periodic bottom periodic periodic periodic periodic periodic top periodic periodic periodic periodic periodic solid phases 1 solid phases random integer randomization 123 from file Grain Growth Microstructure txt grains with stabilisation and voronoi construction further nucleation NO n phase interaction phase interaction phase interaction phase interaction pure with particle with solute drag pinning mobility mobility dg dependent temperature a Grain_Growth_dG_ dependent Mobility_Data temperature conditions 1 1000 G 0 K cm dT dt 0 K s from file isothermal MICRESS User Guide Volume IV MICRESS Examples pu Chapter 7 Grain Growth files restart grains phases interface mobility curvature velocity grain time file von Neumann Mullins output monitoring outputs times times from 0 00 s to 20 s output every 5 s linear step from 0 00 s to 0 4 s output from 20 00 s to 250 s output
37. ir orientation MICRESS User Guide Volume IV MICRESS Examples Pu a Chapter 9 Recrystallisation 93 4 ReX 4 in txt hecrystallisation path presented by the orie output m 20 40 50 80 20 40 60 BO 0 t 120s o e 20 40 60 0 Figure 9 5 recrystallisation path Rex 4 orie mcr MICRESS User Guide Volume IV MICRESS Examples Lu 20 40 60 80 0 20 40 50 80 20 40 so gg 1228 t 20s t 270s chapter 9 Recrystalisation Chapter 9 Recrystallisation 935 5 Recrystallisation path presented by the orie output t 9s t 14s t 30s Figure 9 6 The recrystallisation path Rex 5 orie mcr MICRESS User Guide Volume IV MICRESS Examples mu Chapter 10 Stress 10 Stress 10 1 Description The example Stress dri is concentration coupled and shows the simulation of Eshelby s solution name dri file Stress in txt alloy system Fe C Mn 0 103 wt C in austenite composition 0 49 wt Mn in austenite transition austenite to ferrite with stress Table 14 Example Stress details MICRESS User Guide Volume IV MICRESS Examples mu Chapter 10 Stress 10 2 Simulation conditions name dri file Stress in txt dimension 2D grid size 200x200 cells grid spacing 0 25um interface thickness 5 5 cells bounda
38. istri bution control Table 2 Overview of the solidification features covered in the MICRESS examples boundary conditions SS Le SAS SSS E d T phase interaction modes o LL tt LLL 4 LLL 441 o LL 114 4 4 41 1 1 1 1 1 11 1 4114 1 1 4 1 11 i HW MICRESS User Guide Volume IV MICRESS Examples 6 Chapter 4 Delta Gamma 4 Delta Gamma 41 Description Delta Gamma dri is a 2D simulation of the directional solidification of a ternary steel model alloy containing carbon and manganese The simulation shows the solidification of a dendrite and the subsequent peritectic reaction to the y phase The simulation is performed as concentration coupled and makes use of the 1 far field approximation and the moving frame option It is coupled to Thermo Calc N name dri file Delta Gamma dri alloy system Fe C Mn Steel Ges5 98 at96 Fe composition 1 at C 1 at Mn e solidification peritectic transformation Figure 4 1 Example Delta Gamma phas dendritic solidification at a time of 25 s left and peritectic reaction at a time of 32 5 s right MICRESS User Guide Volume IV MICRESS Examples pu lt Chapter 4 Delta Gamma 4 2 Simulation conditions name dri file Delta Gamma dri dimension 2D grid s
39. ize 145x1500 cells grid spacing interface thickness 4 cells Fast symmetric West symmetric boundary conditions bottom insulated top fixed solid phases Two solid phases 6 phase y phase deterministic placement of 1 grain of phase round 0 0 position x 0 5 z 0 5 stabilisation of the grain grain input further nucleation y phase seed position interface curvature undercooling max 5 seeds AT 1 K rotation angle 5 to 5 between 1765 K and 1700 K temperature conditions 1796 250 K cm dT dt 1 K s files restart phases average table fraction interface driving force concentrations C Mn times output gt fixed output at 0 01 s 1 0 s and 2 5 s gt from 2 5 s to 35 s output every 2 5 s linear step gt from 35 s to 50 s output every 5 0s linear step special features concentration coupling 1d far field diffusion approximation 500 cells distance from the front 200 um gt thermodynamic coupling GES file Steel GES5 gt moving frame distance from the upper boundary 200 um MICRESS User Guide Volume IV MICRESS Examples mu Table 3 Example Delta Gamma simulation conditions parameters RE Chapter 4 Delta Gamma 43 Visualisation of the results e Solidification sequence is presented by the phas output 1 interface 0 liquid 1 phase 2 yphase UN 1 UN EN 1 Figure 4 2 The Delta Gamma solid
40. ked in the MICRESS generated output to check if it matches the input structure with sufficient accuracy and possibly adjust the input structure e g by using another threshold when marking cells as solid The steady start option is employed to establish the flow pattern at time step 0 With this option MICRESS tries to determine a large value for the time steps used to establish a steady pattern for these steps the time limits do not apply The number of preliminary time steps is chosen with the pre iter option it should be large enough to establish a steady fluid flow pattern When this is the case the final time steps converge very fast so verbosity should be kept at 2 for verification In some cases the automatic time steps may become too large to achieve convergence especially when eddies are forming If this is the case freeze the phase field as in the cylinder examples start with small time steps and converge the flow pattern in successive runs using restarts while adjusting time steps and convergence parameters 1 Other filters hat may prove helpful transform for symmetry operations append datasets to combine mirrored datasets with the original calculator to generate the grain number e g from phase fractions and pass arrays to select only the desired output array Profile adjustment can take some time for large structures so you might want to generate a restart file with adjusted profile and start from
41. l Il MICRESS Post processing explains the possibilities for analysing MICRESS output results MICRESS User Guide Volume IV MICRESS Examples P Chapter 2 What s new 2 Whats new This section will be regularly up dated with new examples for new features of MICRESS once they have become established examples For Release 6 2 the Gamma Alpha family of examples has been completely reworked Although the former versions of this family s examples Gamma Alpha dri Gamma Alpha TC dri Gamma Alpha NPLE dri amma Alpha PARA dri proved to be a good basis for MICRESS courses and for demonstrating the general input file structures the choice of parameters was quite extreme and thus not optimal for starting own research in the field of gamma alpha transformations Consequently the fundamental changes chosen were to strongly increase the alloying level in order to increase solutal control and to implement the nple no partitioning local equilibrium redistribution model as default To obtain meaningful results at a high computational performance which is important for hands on courses the thermal boundary conditions further have been changed to isothermal while keeping the initial microstructure and the basic design of the nucleation types unchanged The new members of the Gamma Alpha family now are Gamma Alpha dri Gamma Alpha dri Gamma Alpha PARA dri and Gamma Alpha PARATO A completely new example CMSX4 dri has been a
42. le Ripening in txt Eutectic in txt dimension 2D grid size cells 100x1x100 grid spacing 0 1 interface thickness cells 4 boundary conditions BCs Fast periodic symmetric phase field West periodic symmetric BCs bottom periodic periodic top periodic periodic Fast periodic periodic concentration West periodic periodic field BCs bottom periodic periodic top periodic periodic solid phases 1 solid phase A1 2 solid phases recrystallisation random placement of grains round integer for randomization 10 stabilisation of the grains Voronoi construction further nucleation enabled Nt ou nucleations 25 temperature conditions T 845 G 0 K cm dT dt 0 K s latent heat enabled files restart grains phases average fraction output interface output driving force output mobility output curvature grain time file concentration concentration of the reference phase linearization output monitoring outputs output times times fixed output at 0 001 s from 0 s to 0 02 s output every 0 005 s logarithmic step from 0 02 s to 0 55 s output every 0 02 s outputs at 1 4142 s and 1 s linear step concentration coupling gt NO 1d far field diffusion approximation gt thermodynamic coupling enabled Seta Bin Gesb datafile gt NO moving frame special features Table 17 Example coupling field parameters MICRESS User Guide Volume IV MICRE
43. lisation of the results He eene ince idc dw heus 26 6 3 1 Gamma Alpha dri and Gamma Alpha dri 26 6 3 2 GammaAlpha Cementite dri and _ _ _ 29 6 3 3 Gamma Alpha tress ree ETT 32 T GOW RE TUER 34 ET BescHnpBOIissunnsnnnsdnas secado 34 72 Simulation 35 7 3 Visualisation of the results eese nnnm 37 Pure grain growth and grain growth with particle pinning and solute drag 37 k32 Bialn Grow Drag da dp XE eset dot 38 38 Ee POY EE 38 ID E 38 Figure 1 The grain growth sequence with driving force dependent mobility Grai Grewitr SoDUEe 6 KO D etre betreut 38 7 3 3 GOV Ulin IE esc ie ae UND LAND UNI LAM ae LEM ae 39 5 Phosphorous PeaK WR eee enn 41 nu 0r etx D LC CENE 41 82 Simulation COMAITIONS cccccccecssccscceeceecsessseseeceeeeseceesenscaesasseceneeaecaesneenecaesaesanseeesuesaeseeesnesaeeeeeanens 42 83 Visualisation of the results eese sinn nina nai tn asta a snas 44 3 3 1 RD m POR 44 0 3 2 Po Peak 2D n um 45 9
44. me IV MICRESS Examples pu chapter 7 GrimGrow Chapter 7 Grain Growth 73 3 Grain Growth Profiles in txt e Grain growth Grain Growth Profiles korn txt t 0s t 0 32s t 1s Figure 2 The grain growth path with temperature dependent mobility MICRESS User Guide Volume IV MICRESS Examples pu 6 Chapter 7 Grain Growth e lemperature distribution Grain Growth Profiles temp txt LO un D C C CO CO C C C C C D D LC t 0s t 0 32s t 1s Figure 3 The temperature profiles for different time steps MICRESS User Guide Volume IV MICRESS Examples pu 6 Chapter 9 Recrystallisation 8 Phosphorous Peak 8 1 Description These two examples P Peak 1D and 20 dri show full multicomponent diffusion with coupling to Thermo Calc using industrial steel grades The first example is one dimensional and provides a ready benchmark against DICTRA ifi P Peak 1D in txt name dri file P Peak 2D in txt alloy system Fe C Mn Si P Fe C Mn Si PGes5 0 4 wt C i 0 8 wt Mn composition 0 wt Si 3 107 wt P transition solidification Table 10 Example Phosphorous Peak details modelled phases are liquid red ferrite orange and austenite bright MICRESS User Guide Volume IV MICRESS Examples P x Chapter 9 Recrystallisation 82 Simulation conditions
45. n tables times linear step 5s till 15 s times linear step 0 5s till 2 5 s In addition concentration coupling fluid flow special features gt output viewable with ParaView IDEE uu piso limited by solver cycles interface stabilisation analytical starting conditions for fluid flow Table 22 Example Delta Gamma simulation conditions parameters 143 Tweaking performance oince 3D simulations are computationally intensive some measures are taken to reduce computation time especially for fluid flow calculations The large grid spacing of 2 is most helpful in this respect since it reduces the number of simulations cells and allows larger time steps in the flow and diffusion parts of the simulation To avoid deformation of the phase field at the interface on such a coarse lattice interface stabilisation is employed by supplying an extra parameter for the interfacial energy The grid spacing for fluid flow is doubled by means of the flow coarse option further reducing the number of simulation cells The orientation of the dendrite is chosen so that symmetry planes of the cubic anisotropy coincide with symmetric domain boundaries to reduce the simulation domain For the forced fluid flow a fixed velocity in z direction was set at the B and I boundaries Using a pressure differential would lead to a quickly accelerating flow especially in the beginning of the simulation when the grain i
46. ncentration Gamma Alpha Cementite LinTQ in txt Manganese Gamma Alpha CementiteTQ concentration Manganese concentration 99 Figure 6 4 Concentration Gamma Alpha Cementite with linearized LinTQ and non linearised TQ concentration coupling time step 35 sec in both cases MICRESS User Guide Volume IV MICRESS Examples pu 6 Chapter 6 Gamma Alpha MICRESS User Guide Volume IV MICRESS Examples P Chapter 6 Gamma Alpha 6 33 Gamma Alpha Stress dri e ransformation sequence presented by the phas output 1 mterface 0 met assigned 1 gamma 2 alpha 3 eementite Cx C C 1 08 t 6s B tw CO _ t 10s ts 198 Figure 6 5 The phase transition sequence Gamma Alpha Stress in txt MICRESS User Guide Volume IV MICRESS Examples pu chapter 6 Gamme Apha Chapter 6 Gamma Alpha e Von Mises stress X Co 400 600 200 200 s st 7ou H ee t 0s t 5s 400 600 500 200 t 10s t 15s Figure 6 6 Equivalent stresses for the Gamma Alpha Stress example MICRESS User Guide Volume IV MICRESS Examples pu 6 Chapter 7 Grain Growth 7 Grain Growth 7 1 Description The group of examples Grain Growth Grain Growth Grain Growth Particle Pinning
47. nditions BCs phase field BCs temperature field BCs East insulation West insulation bottom insulation top insulation Fast insulation West bottom insulation insulation top insulation solid phases one solid phase a pure substance grain input recrystallisation NO deterministic placement of 1 grain round 0 0 position x 0 0 z 0 0 r 20 um stabilisation of the grain Voronoi construction further nucleation NO temperature conditions To pottom 999 665 999 665 output files restart data grain number output phases fraction average fraction table interface driving force mobility curvature velocity grain time file temperature monitoring outputs times output at 0 000001 s 0 00001 0 00005 0 0001 0 0002 0 002 fixed output time step 1E 7 special features gt temperature coupling gs gt 1d far field diffusion approximation NO gt thermodynamic coupling NO gt moving frame NO MICRESS User Guide Volume IV MICRESS Examples mu Table 19 Temperature Example simulation conditions 6 Chapter 12 Temperature 12 3 Visualisation of the results e he temperature field as taken from the temp output t 0s t 1 0 x 104 6s t 9 9999997E x 104 6s 1 4 9999999 x 10 5s t 9 9999997E X 10 5s t 1 9999999E x 10 4 Figure 12 1 lemperature temp mcr MICRESS
48. ness but mainly for increasing performance and numerical stability while not having any substantial impact on the simulation results MICRESS User Guide Volume IV MICRESS Examples mu 6 Chapter 13 Ni based Alloy name dri file 5 dri txt alloy system CMSX4 Ni 6 5 Cr 9 Co 0 6 Mo composition 6 W 6 5 5 6 1 Ti 396Re 0 196Hf phenomenon Solidification and formation of interdendritic Table 20 Example CMSX4 details 13 2 Simulation conditions name dri file 5 dri txt dimension 2D grid size 1000x1x520 cells grid spacing lum interface thickness 2 5 cells boundary conditions BCs phase field BCs East insulation West insulation temperature field BCs bottom insulation top insulation East insulation West insulation bottom insulation top insulation solid phases FCC_A1 L12 y recrystallisation NO un deterministic placement of 14 small grains at centers of the dendrites grain input further nucleation 112 at interfaces temperature conditions 1022 constant cooling rate 0 65 K s no gradient MICRESS User Guide Volume IV MICRESS Examples mu C Chapter 13 Ni based Alloy databases thermodynamic TTNI7 diffusion data MOBNI1 special features interaction diagonal mode for partition matrix gt Workspace size exten
49. on The choice of boundary conditions has an impact on convergence and performance for larger velocities resulting from higher pressure gradients the time steps must be smaller oince a stationary laminar flow with Re 1 is expected the combined solver is used The time step size was determined in test runs For the convergence criteria limit of 102 5 is set for the continuity equation matching limits for velocity and pressure are found by observing convergence in tests with higher verbosity A value of 0 97 for pressure underrelaxation is usually a good choice with the combined solver 15 12 Formation of a Karman vortex street his is an example of a dynamically changing flow pattern resulting from a stationary geometry This may happen when the Reynolds number is of O 10 or higher depending on the geometry In this case an inlet with a fixed velocity and an outlet with a fixed pressure are set For this example the piso solver is employed because of the higher Reynolds number For time stepping a CFL limit for of 0 3 is used Convergence criteria are chosen to match for a limit of 10 5 for the continuity equation In this example the symmetric starting conditions result in a symmetric nearly static state early in the MICRESS User Guide Volume IV MICRESS Examples pu Chapter 15 simulation until breaking of symmetry leads to dynamic changes and finally Karman vortex shedding Notably convergence behaviour c
50. ontrol Table 1 Overview of the solid state transformation features covered in the MICRESS examples MICRESS User Guide Volume IV MICRESS Examples 6 Chapter 3 Examples Overview HIN se asy DC PINENNE _ EN DIEN JENNI E Mp 41092 gjy pinbi pijos m fa 92 IS pinbi pijos EIS up Budden isiy SZ IS ist m E D E pZ noy Jp pexeinb3 nav amp mov EXE ES ud Ei mn EN EN EN determinis tic En LL m xxn Li oT s x ME recrystallisation BE Example number alloy transformation concentration coupling temperature coupling stress field fluid flow MICRESS User Guide Volume IV MICRESS Examples chapter Examples Overview Chapter 3 Examples Overview from file voronoi mM Bn con nucleation model thermodynamic anisotropy model tempera ture moving latent heat The particle pinning red
51. onvergence at a simulation time when some solid has formed In this simulation the number of inner and outer piso cycles is set as limiting element outer piso cycles were set to 1 inner cycles to 3 after finding that 2 inner cycles were insufficient to reach convergence A value of 10 5 was chosen to limit the continuity error Pressure and velocity criteria were then adjusted until a sweet spot was found where the accuracy was sufficient and stricter values mainly resulted in more cycles of the linear solvers 144 Results Figure 14 1 shows the simulated dendrite without flow at the end of the simulation In this stage of the simulation growth rate is mostly governed by cooling rate and dendritic ripening can be observed In Figure 14 2 the first 2 5 seconds of the simulation with and without flow are shown side by side For better comparability the cooling rate in Dendrite AISi 3D dri was changed to 0 1K s to match that of Dendrite AISi 3D flow dri As one can see the advective species transport shifts the concentration in the direction of the melt flow which in turn causes asymmetric growth of the dendrite QN j J Figure 14 1 Dendrite after 15s simulation time MICRESS User Guide Volume IV MICRESS Examples P Figure 14 2 Simulation of dendritic solidification with and without forced melt flow compared side by side Fluid flow is indicated by arrows and enhanced concentration is indicated by a dark halo The d
52. or temperature coupling and release of latent heat Another feature of this example is the use of categorized seeds AlCu_dri txt name AlCu Equiaxed dri txt AlCu Tempid dri txt alloy system Al Cu Al_Cu Ges5 97 at Al composition 3 at t Cu transition solidification Table 4 Aluminium Copper examples MICRESS User Guide Volume IV MICRESS Examples pu Chapter 5 Aluminium Copper 5 2 Simulation conditions name dri file AlCu_dri txt AlCu_Equiaxed_dri txt AlCu_Temp1d_dri txt dimension 2D grid size 300x300 cells 200x200 cells grid spacing 2um 0 5um interface thickness 4 cells 3 5 cells boundary conditions BCs Fast symmetric periodic periodic West symmetric periodic periodic phase field BCs bottom symmetric periodic insulation top symmetric periodic insulation Fast symmetric periodic periodic West symmetric periodic periodic concentration field BCs bottom symmetric periodic insulation top fixed periodic insulation solid phases 1 solid phase fcc 2 solid phases deterministic placement En grain further nucleation NO further nucleation enabled seed position bulk seed density nucleation model applied grain input integer for randomization 13 integer for randomization 111 max 1000 simultaneous nucl
53. pter 9 Recrystalisation Chapter 9 Recrystallisation e Concentration evolution presented for the conc2 Mn t 0s t 20s t 00s t 1000s Figure 8 3 The concentration field for Manganese P_Peak_2D_conc2 mer Mn 1 C 2 Mn 3 P and 4 Si MICRESS User Guide Volume IV MICRESS Examples pu 6 Chapter 9 Recrystallisation 9 Recrystallisation 9 1 Description The five examples ReX 1 ReX 2 ReX 3 ReX 4 dri and ReX 5 dri illustrate various topics related to recrystallisation All examples show the influence of misorientation and stored energy on recrystallisation growth and the use of the Voronoi criterion In addition ReX 1 and ReX 5 demonstrate the use of the seed undercooling nucleation model ReX 1 in txt ReX 2 in txt name dri file ReX 3 in txt ReX 4 in txt ReX 5 in txt Not specified e g steel Not specified e g ferrite or austenite composition phenomenon recrystallisation Table 12 Example Recrystallisation details MICRESS User Guide Volume IV MICRESS Examples pu lt Chapter 9 Recrystallisation 92 Simulation conditions 2 N el E gt lt gt lt gt lt gt lt gt lt CD CD ab cc cc
54. roblem of moving phase boundaries The microstructure evolution is governed essentially by thermodynamic equilibria diffusion and curvature In case of multicomponent alloys the required thermodynamic data can either be provided to MICRESS in the form of locally linearized phase diagrams or by direct coupling to thermodynamic data sets via a special interface developed in collaboration with Thermo Calc AB Stockholm MICRESS is based on the multi phase field method which defines a phase field parameter for each phase involved The phase field parameter describes the fraction of each phase as a continuous function of space and time Each single grain is mapped to a distinct phase field parameter and is treated as an individual phase A set of coupled partial differential equations is formed which describes the evolution of the phase field parameter together with concentration temperature stress and flow fields The total set of equations is solved explicitly by the finite difference method on a cubic grid 2D and 3D simulations are possible The size of the simulation domain the number of grains phases and components is restricted mainly by the available memory size and the CPU speed ouggestions for improvements of the manual or comments on the manual are highly welcome to documentation micress de MICRESS User Guide Volume IV MICRESS Examples Chapter 1 Introduction MICRESS handles e 1 2 and 3 dimensional c
55. ry conditions BCs phase field BCs concentration field BCs East insulation West insulation bottom insulation top insulation East insulation West insulation bottom insulation top insulation solid phases 2 solid phases austenite initial matrix and ferrite growing grain input recrystallisation NO deterministic placement of one austenite grain round 1000 position x 0 0 z 0 0 and one ferrite grain round 2 5 um x 25 5 2 24 2 stabilisation of the grain no Voronoi construction further nucleation NO latent heat NO temperature conditions T 1100K G 0 K cm dT dt 0 K s phase diagram input linear notation of eigenstrain volume output files interface driving force concentration normal stress von Mises stress normal displacement times fixed output at 0 01 s gt automatic output special features gt concentration coupling stress calulation gt 1d far field diffusion approximation NO gt thermodynamic coupling NO gt moving frame NO Table 15 Example 01 Delta Gamma field parameters MICRESS User Guide Volume IV MICRESS Examples mu q Chapter 10 Stress 10 3 Visualisation of the results e he von Mises stress field presented by the vM output ES 2 c c E co Cp c E l EE LLI Es m E DE 92 T
56. s pu 6 Chapter 6 Gamma Alpha 6 Gamma Alpha 6 1 Description A series of examples Gamma Alpha Gamma_Alpha_TQ_dri Gamma Alpha PARA Gamma Alpha and Gamma Alpha Stress simulates the transformation for ternary steel model alloy iron carbon and manganese The first two examples are intended to demonstrate the difference between MICRESS simulations with and without coupling to Thermo Calc Both are concentration coupled either linearized phase diagrams OR database use and demonstrate the use of the seed undercooling nucleation model Important for solid state transformations in systems with slow and fast diffusing elements is the use of the nple NPLE non partitioning local equilibrium redistribution model The next two examples instead use the para equilibrium models The last of the examples Gamma_Alpha_Stress_dri shows how stress coupling can be included A variation of the Gamma Alpha the GammaAlphaCementite LinTQ demonstrates the application of a combination between linearized phase diagrams AND coupling to a thermodynamic database Furthermore cementite is added as third solid phase Another variation of the Gamma Alpha example GammaAlphaCementiteTO utilizes full coupling to thermodynamic database GammaAlpha_Pearlite dri furthermore demonstrates the use of the diffuse effective phase
57. s small and frictional forces are negligible So an inflow with a fixed velocity was chosen For the outflow conditions a fixed outflow velocity was chosen for two reasons Fixing in and outflow velocities leads to faster convergence of the flow solver also it is more consistent with periodic boundary conditions for the concentration field to match the velocities of the outflow with those of the inflow MICRESS User Guide Volume IV MICRESS Examples pu AK Chapter 14 These boundary conditions lead to a uniform velocity of the fluid at the start of the simulation when there is no solid phase This is determined analytically using the ana_start option Numerical improvement of the analytical solution is unnecessary and avoided with pre iter 0 For a rough estimate of the Reynolds number the cross section can be used as a diameter 4 320 so Re d v v 320um 1mms 3 7 10 cm s 0 86 50 in this case piso and combined solver should perform about equally well this example uses the piso solver To find optimal values for time stepping tests were done starting with CFL Limits C 0 3 and C 0 25 equating to a maximum time step size 6 AX 4 n 0 25 4um 3 7 10 cms 1 10 s By observing performance when rising the maximum step size a combination of C 20 2 and 5 10 s was found to optimize performance To find proper convergence criteria some test runs were made with verbosity 2 observing the c

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