MICRESS Forum

Hi,

I was asked by Hisao to answer a question in the forum which I got by email:

I want to simulate the sintered oxides.
I attach the PPT.
Do you have any good examples?

Sintering can probably not be simulated with MICRESS, because there is a gas phase which is not preserved. One would have to invent a pseudo-phase diagram which would have similar properties and which would lead to the removal of the gas phase - but probably this would be far away from the physics of sintering...

Dear Bernd,

I got a question about the sintering process. I am about to simulate the sintering procedure of super saturated Mo solid solution, in which the gas phase does not play a role! Is this possible to do it my Micress? During the high temperature sintering process (>1600 C) the solid solution would decompose into three solid phases! a part of dissolved component would get out of the lattice and will perform other solid phases. Moreover, how can I apply the external pressure? the process is done under high pressure situation! Do you have any advice?

Regards,
Omid.

Hi Omid,

it does not matter whether there is a gas or vacuum. Typically, sintering implies some densification of the material, i.e. there are free surfaces which are reduced during sintering. This is something which MICRESS cannot do.

The decomposition of the Mo-Matrix into different phases is another thing which of course can be done by MICRESS. The question is whether you have a thermodynamic database or whether you need to construct a linearized phase diagram description. In the second case it could get complicated...

Applying pressure is simple if the database contains volume information. Otherwise, you could estimate the volume changes for the individual phase transformations and describe the effect of pressure as offsets to the driving force ΔG of the individual phase pairs.

Bernd

Dear Bernd,

Do you have any advice for such a kind of modeling? I mean something rather than the Micress which can help me. Just regarding my Micress model, I have a linearized phase diagram description included and there is no database!

Regards,
Omid.

Unfortunately not.
If sintering is the main question you want to address, it does not really make sense to try it with MICRESS. At least I do not see how you could include the important physical phenomena...

Bernd