Slip System Analysis in $$\alpha$$-Alumina edit page author: Ruben Wagner, Robert Lehnert, TU Bergakademie Freiberg, Institute

of Materials Engineering, Germany

## Data Import

The following EBSD maps has been measured by Ruben Wagner TUBAF, Institute of Materials Engineering, 2022 within the project SFB 920. It shows an alumina inclusions in 42CrMo4 steel after nanoindentation.

## Correct for misindexiation due to pseudosymmetry

Looking at the raw data we observe several neighbouring measurements that are exactly 180 degree rotated with respect to each other. This is indicated by color coded grain boundaries. It is suspected that this misorientation occurs as the EBSD system has a hard time to distinguish the Kikuchi pattern of two orientations that differ by a rotation about the c-axis by 180 degree.

In order to correct for this misindexiation we proceed as follows

# Identify grain boundaries due to pseudo symmetry
# Merge grains with common pseudo symmetry grain boundaries and
compute the dominant orientation of the merged grains
# Correct the EBSD data according to the pseudo symmetry

1. Identify boundaries between pseudosymmetric grains

2. Merge grains with common pseudo symmetry grain boundaries This results is two big grains as visualised below

3. Correct the EBSD data according to the pseudo symmetry

## Data cleaning

We perform some more data cleaning steps including

1. removing too small grains
2. filling of the not indexed pixels

## Schmid Factor Analysis

Next we compute the the active slip system during pressure in z-direction. The possible dominant slip systems in alumina are described in Mao2011 and 2012 as

Next we determine the Schmid factor for all symmetrically equivalent slip systems.

Finally, we plot the trace of the slip planes together with the slip direction in the EBSD map.