Order disorder transformation

[Rahul M R]

Hi all,

I am new in this forum. I need to use micress for simulating order to disorder transformation, please provide some example file to start the same.

Thanks

Rahul

[Bernd]

Dear Rahul,

Welcome to the MICRESS forum.

If you plan to simulate an order-disorder transformation at or close to the critical point, i.e. a spinoidal composition starting with fluctuations in a homogeneous phase and ending in a two phase microstructure, MICRESS is probably not the best software. But if you plan to simulate e.g. precipitation of an ordered phase like gamma'-Ni3Al from a disordered phase like gamma, and you are not primarily interested in the precipitation process itself but in the growth or ripening of this phase, then MICRESS is what you need.

Can you specify a bit more clearly what you plan to simulate?

Best wishes
Bernd

[Rahul M R]

Dear Bernd,

Thanks for your prompt replay.

Actually i am interested in the following transformations

1) Disorder to order transformation (e.g.precipitation of an ordered phase like γ'-Ni3Al and its growth)

2) Order to disorder transformation in some alloys (not spinoidal composition decomposition)

Thanks

Rahul

[Bernd]

Dear Rahul,

currently, we do not have a standard example for this type of reaction. But what is closest to that is the example CMSX4_dri, which is available in the "Examples" directory in your installation or as download on the MICRESS webpage (Downloads) and which describes the solidification of CMSX4. In this case, gamma' precipitates from the liquid phase in kind of a eutectic reaction.
I did similar simulations in Ni-base superalloys at different scales including nucleation of gamma' inside the solid dendrite, which is the way how we typically describe this type of spinoidal decomposition in MICRESS. Unfortunately, these simulations have been done for industry, so I am not allowed to provide you with the corresponding input file. But, in principle, it is nothing more than adding a nucleation type for gamma' inside gamma using e.g. a seed density nucleation model. So, there should be no problem for you, with our help, to design such simulations. But, please remember, we typically do not treat decomposition of a homogeneous phase starting from fluctuations, but instead use nucleation of discrete particles instead.

Bernd