Search found 1203 matches

by Bernd
Thu Apr 15, 2021 2:26 pm
Forum: solidification
Topic: Dendritic growth not observed
Replies: 1
Views: 10

Re: Dendritic growth not observed

Yongliang Ou, Most probably, the interface mobility is reduced due to a too high value of the minimum time step. Please note that the definition of a minimum time step is done for performance reasons only and cannot be done before the setup of the simulation is finished successfully. Time stepping c...
by Bernd
Tue Apr 13, 2021 5:49 pm
Forum: solidification
Topic: Cooling rate
Replies: 6
Views: 41

Re: Cooling rate

Dear Lv Shaojie, sounds as if you could use an approach like I did some years ago: B.Böttger, M.Apel, B.Santillana, and D.G.Eskin Relationship Between Solidification Microstructure and Hot Cracking Susceptibility for Continuous Casting of Low-Carbon and High-Strength Low-Alloyed Steels: A Phase-Fiel...
by Bernd
Tue Apr 13, 2021 3:01 pm
Forum: solidification
Topic: Cooling rate
Replies: 6
Views: 41

Re: Cooling rate

Dear Lv shaojie, The cooling rate which you apply in MICRESS refers to the temperature at the bottom of the simulation domain, irrespective of the phase or material which is there. If you furthermore define a temperature gradient (in z-direction of the domain), then the temperature in other regions ...
by Bernd
Tue Apr 13, 2021 11:13 am
Forum: phase-field model
Topic: MICRESS simulated precipitation(The second phase)
Replies: 3
Views: 38

Re: MICRESS simulated precipitation(The second phase)

Dear Lv shaojie, If you are interested in precipitation of a second phase during grain growth, you probably are thinking about particle pinning effects on grain growth. In MICRESS, this topic can most easily be addressed by using the "particle_pinning" model. Then you do not have to treat precipitat...
by Bernd
Tue Apr 13, 2021 11:03 am
Forum: solidification
Topic: Cooling rate
Replies: 6
Views: 41

Re: Cooling rate

Dear Lv shaojie, Growth rate and cooling rate are two completely different quantities, which are linked by the temperature dependency of the driving force for phase transformation. Admittedly, in solidification processes this link is quite strong: d(ΔG)/dT = ΔS ~ 1 J/(Kcm 3 ) As I explained for your...
by Bernd
Tue Apr 13, 2021 10:53 am
Forum: phase-field model
Topic: Cooling rate representation method
Replies: 1
Views: 20

Re: Cooling rate representation method

Dear Lv shaojie, The phase-field equation of MICRESS is based on a Helmholtz energy approach, which means that temperature is an independent variable and thus is considered as a boundary condition. This means, that most typically temperature is defined as an initial temperature cooling rate, althoug...
by Bernd
Mon Apr 12, 2021 2:47 pm
Forum: recrystallisation/grain growth
Topic: some qustions of recrystallisation
Replies: 12
Views: 2079

Re: some qustions of recrystallisation

Hi Kamran, Based on the explanations for your process, I propose the following procedure: 1.) You start from a suitable MICRESS standard example, I would suggest A004_Gamma_Alpha_TQ_dri. You can adapt the chemistry of your system as well as the length scale to your needs. 2.) Interchange ferrite and...
by Bernd
Mon Apr 12, 2021 9:20 am
Forum: recrystallisation/grain growth
Topic: some qustions of recrystallisation
Replies: 12
Views: 2079

Re: some qustions of recrystallisation

Dear Kamran, I am still struggling to understand the physical background of the process which you describe. What I understand is that you assume that there are two competitive processes: the recrystallisation of martensite (i.e. nucleation and growth of new martensite grains, with a reX-energy lower...
by Bernd
Sun Apr 11, 2021 8:21 pm
Forum: solidification
Topic: Seed-density and seed-undercooling models
Replies: 13
Views: 259

Re: Seed-density and seed-undercooling models

Dear Mauro, No, there is not yet a standard MICRESS example existing for these types of temperature cycling. Basically, thermal cycling is achieved in MICRESS by using time-dependent temperature boundary conditions. Depending on the type of process, they can be applied in different ways. In case of ...
by Bernd
Sun Apr 11, 2021 7:54 pm
Forum: recrystallisation/grain growth
Topic: some qustions of recrystallisation
Replies: 12
Views: 2079

Re: some qustions of recrystallisation

Dear Kamran, To be honest, the information you provide confuses me! You say, recrystallisation of martensite is always connected with transformation to austenite. This means that we don't speak about normal recrystallisation but about a phase transformation. However, the data for initial grains and ...