New option: dependent

new developments, future functionalities, hints for further applications of MICRESS
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Bernd
Posts: 1074
Joined: Mon Jun 23, 2008 9:29 pm

New option: dependent

Post by Bernd » Thu Jul 02, 2009 12:03 pm

Hi all

In some phases like Ti(N,C), two elements (N,C) are located on the same sublattice, so that their composition in the phase is directly dependent on each other. If during a MICRESS simulation of a steel or nickel-base alloy this phase occurs, the multi-binary extrapolation scheme of MICRESS is not optimal, because each component is calculated with respect of the matrix element which is nearly insoluble in the Carbide.
The normal procedure in MICRESS is to set Ti, N and C as stoichiometric and provide a sufficiently high relinearisation frequency. But, especially at lower temperature where the N composition e.g. in the fcc matrix is very low, one would need an extremely high relinearisation frequency to obtain the correct C/N ration in the carbide. Then the new hidden expert option "dependent" may help, which applies a modified redistribution scheme:

e.g.:

# Phase diagram - input data
# ==========================
#
# List of phases and components which are stoichiometric:
# phase and component(s) numbers
# List of concentration limits:
# <Limits>, phase number and component number
# End with 'no_more_stoichio' or 'no_stoichio'
1 1 2 3 4 5 6 7 8 9
3 1 2 3 4 5 6 7 8 9
4 1 2 3 4 5 6 7 8 9
5 1 2 3 4 5 6 7 8 9
6 1 2 3 4 5 6 7 8 9
7 1 2 3 4 5 6 7 8 9
8 1 2 3 4 5 6 7 8 9
dependent 1 1 8
Limits 0 6
# Minimal allowed value [at%]
1.000000000000000E-006
# Maximal allowed value [at%]
100.000000000000
Limits 1 4
# Minimal allowed value [at%]
45.0000000000000
# Maximal allowed value [at%]
55.0000000000000
Limits 1 8
# Minimal allowed value [at%]
10.0000000000000
# Maximal allowed value [at%]
55.0000000000000
no_more_stoichio


In this case, in phase 1 (first parameter), component 1 is modelled as dependent from component 8.

Caution: This is a not fully tested expert option!


Bernd

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