Mobility for austenite grain growth

ripening phenomena, dislocations, grainboundary topology
Raina
Posts: 13
Joined: Thu May 21, 2015 2:03 am
anti_bot: 333

Re: Mobility for austenite grain growth

Post by Raina » Thu Oct 01, 2015 3:02 am

Hello,

I'm using Micress ran two simulations. One is for ideal isotropic grain growth and another is for ideal grain growth with texture.

For the second simulation, I set initial structure random distributed and the misorientation = 30. For modification for surface energy and mobility, I chose "factor" and both prefactor = 1.0.

Here is part of my input file for second case:
# Phase data
# ==========
# Number of distinct solid phases?
1
#
# Data for phase 1:
# -----------------
# Simulation of recrystallisation in phase 1?
# Options: recrystall no_recrystall [verbose|no_verbose]
no_recrystall
# Is phase 1 anisotrop?
# Options: isotropic anisotropic faceted antifaceted
anisotropic
# Crystal symmetry of the phase?
# Options: none cubic hexagonal tetragonal orthorhombic
cubic
# Should grains of phase 1 be reduced to categories?
# Options: categorize no_categorize
no_categorize

and

# Shall misorientation be considered?
# Options: misorientation no_misorientation [transition LAB/HAB in degree]
misorientation 30
# Input of the misorientation coefficients:
# Modification of surface energy for low angle boundaries
# Options: factor Read-Shockley
factor
# prefactor of surface energy:
1.0000
# Modification of the mobility for low angle boundaries
# Options: factor Humphreys [min_reduction + parameters B and N (default: min_red=0. B=5.0 N=4.0)]
factor
# prefactor of the mobility for low angle boundaries
1.0000

The grain size distribution for first case seems quite well, but later I found that the grain area distribution for the second scenario is not centred at 0, which confuse me a lot. Attached are the grain area distribution for both cases.

Is my code wrong? Or something behind the instructions I've ignored ?

Thanks,

Raina
Attachments
2.jpg
Ideal grain growth with texture
2.jpg (375.25 KiB) Viewed 1432 times
1.jpg
Ideal Grain Growh
1.jpg (395.31 KiB) Viewed 1432 times

Bernd
Posts: 1148
Joined: Mon Jun 23, 2008 9:29 pm

Re: Mobility for austenite grain growth

Post by Bernd » Thu Oct 01, 2015 6:06 pm

Hi Raina,

Why do you compare a radius distribution to an area distribution? Obviously, they cannot be the same.
And why do you expect the area distribution to be centered around 0? How can an area of a grain be negative? Or did you mean "centered around 1"?

What I would expect if you put factors of 1 to the misorientation model is identical results for both cases (if the initial microstructure is otherwise identical) . And I would not be astonished if the curves were really identical if you would plot both for radius or area only...

Bernd

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