### criterion_higher / criterion_lower

Posted:

**Sun Apr 01, 2018 12:45 am**Hi all,

one of the new options of MICRESS Version 6.4 is the possibility to use relative composition criteria instead of absolute limits. This option is very helpful for preventing switching between composition sets if a significant difference in the solubility for a specific element can be identified. If e.g. it is generally true that gamma' has always a higher Al content (in at%) than gamma in Ni-base alloys, one could use:

criterion_higher 2 1 5

or

criterion_lower 1 2 5

if phase 2 is gamma', phase 1 is gamma, and element 5 is Al. If the criterion is violated, an 6-digit error number starting with 1 would be shown:

error = 1020105

It should be noted that this criterion only applies for 2- or multi-phase equilibria where phase 1 and phase 2 are included. This would also include calculation of diffusion coefficients for gamma or gamma' if "diff_comp_sets" is enabled.

However, nucleation of gamma' from the melt still could occur with the wrong composition!

Bernd

one of the new options of MICRESS Version 6.4 is the possibility to use relative composition criteria instead of absolute limits. This option is very helpful for preventing switching between composition sets if a significant difference in the solubility for a specific element can be identified. If e.g. it is generally true that gamma' has always a higher Al content (in at%) than gamma in Ni-base alloys, one could use:

criterion_higher 2 1 5

or

criterion_lower 1 2 5

if phase 2 is gamma', phase 1 is gamma, and element 5 is Al. If the criterion is violated, an 6-digit error number starting with 1 would be shown:

error = 1020105

It should be noted that this criterion only applies for 2- or multi-phase equilibria where phase 1 and phase 2 are included. This would also include calculation of diffusion coefficients for gamma or gamma' if "diff_comp_sets" is enabled.

However, nucleation of gamma' from the melt still could occur with the wrong composition!

Bernd