ORTools example scripts
ORTools example scripts
The world of martensitic transformation or phase transition analysis can be difficult to navigate. To help make the analysis accessible, transparent, and easy to comprehend, the ORTools library consists of plug-and-play functions. Example scripts are provided to help demonstrate these functions in action.
It is possible to run the example scripts from start to end, but we encourage you to run the example scripts in sections to understand the correlation between the scripts and the generated results. This will also help you follow the comments, which provide instructions on the various choices to make in the interactive parts of the program and/or help explain the obtained plots and results. In this way, you will learn the syntax applied throughout the scripts as well as the meaning behind the presented results.
Example 10: 03 JUL 2023
Update to Example 1: Parent grain reconstruction using the variant graph approach in lath martensite and child grain id analysis
This script follows the same dataset as that used in the official MTEX example to demonstrate the reconstruction of parent gamma grains from child alpha grains in a lath martensite microstructure. The computeGrainPairs function provides a direct way of calculating the absolute or normalised frequency and boundary segment lengths of grain pairs. The grain pair ids can be defined by the user for variants, crystallographic packets, Bain groups, any other-id type or for groups of id or equivalent id pairs.
Example 09: 06 JUN 2023
Update to Example 1: Parent grain reconstruction using the variant graph approach in lath martensite and habit plane determination
This script follows the same dataset as that used in the official MTEX example to demonstrate the reconstruction of parent gamma grains from child alpha grains in a lath martensite microstructure. The computeHabitPlane function provides a direct way of calculating the habit plane compared to conventional MTEX.
The details related to the habit plane calculation are described in the following paper:
Example 08: 29 MAR 2023
Update to Example 2: Parent grain reconstruction using the variant graph approach in Ti alloys
This script follows the same dataset as that used in the official MTEX example to demonstrate the reconstruction of parent beta grains from child alpha grains in a alpha-beta Ti alloy. The script provides a faster and less involved way of reconstructing this microstructure compared to the triple-point based approach from Example 2.
The details related to the variant graph approach are described in the following paper:
Example 07: 23 MAR 2022
Update to Example 1: Parent grain reconstruction using the new variant graph approach and advanced variant analysis in lath martensitic steel
This script follows the same dataset as that used in the official MTEX example to demonstrate the reconstruction of parent austenite grains from child lath martensite using the new variant graph approach. Compared to the original Example 1, this updated version also features equivalent variant pair analysis and the measurement of lath block widths.
The details related to the variant graph approach are described in the following paper:
Example 7 - Variant graph approach & advanced variant analysis in lath martensitic steel
Example 06: 12 MAY 2021
Two-stage parent grain reconstruction in a TWIP-TRIP steel
This example is of a 10% cold-rolled twinning and transformation induced plasticity (TWIP-TRIP) steel microstructure with a two-step martensitic transformation in which ε martensite formed from γ austenite, and α' martensite formed from ε martensite. ORTools and the MTEX parent grain reconstruction functionalities are used to reconstruct both parent microstructures in a single workflow. Towards the end, it is demonstrated that variant analysis can be conducted on both transformations.
EBSD map courtesy: Pramanik et al. https://doi.org/10.1016/j.msea.2018.06.024
Example 6 - Two-stage parent grain reconstruction in a TWIP-TRIP steel
Example 05: 04 MAR 2021
Partial parent grain reconstruction to clean TWIP-TRIP steel EBSD data
This example is of a 20% cold-rolled twinning and transformation induced plasticity (TWIP-TRIP) steel microstructure presenting with a two-step martensitic transformation in which ε martensite formed from γ austenite, and α' martensite formed from ε martensite. Using the OR peak fitter function, it is discovered that two possible ORs could be in operation for the γ to α' microstructure. The first OR is not a real OR but rather, an "apparent" OR corresponding to pixels that were misindexed as α' during map acquisition even though they notionally belong to γ. The parent phase reconstruction features in MTEX and the "apparent" OR are used to revert these misindexed points to γ. The grain calculation and the OR peak fitter is re-run to show that the "apparent" OR was eliminated.
EBSD map courtesy: Pramanik et al. https://doi.org/10.1016/j.msea.2018.06.024
Example 5 - Partial parent grain reconstruction to clean TRIP-TWIP steel EBSD map data
Example 04: 04 MAR 2021
Predicting the β to α transformation texture in a titanium alloy
In this script, the reconstruction of the prior parent β microstructure from a child α microstructure is repeated as shown in example 2. Examination of the variant distribution shows that strongly preferential variant selection did not occur. Therefore, the transition texture of α can be accurately predicted from the reconstructed β using the plotPODF_transform function. The result shows that the predicted α transition texture is in good agreement with the experimental α texture.
Example 4 - Transformation texture prediction in titanium alloys
Example 03: 04 MAR 2021
Using the OR peak fitter to deconvolute multiple ORs in titanium alloys
In example 2 the α-β Ti microstructure showed two ORs in the OR peak fitter function. In this example, both ORs are investigated to find out which one of them dominated the phase transition. To evaluate the best match, the disorientation between grain boundary misorientations and the OR misorientations in inverse pole figures and on boundary maps are plotted.
Example 3 - Separation of multiple ORs in titanium alloys
Example 02: 03 MAR 2021
Parent grain reconstruction and variant analysis in titanium alloys
This script follows the same dataset and steps that are used to demonstrate the reconstruction of β grains from an α microstructure in the official MTEX example for phase transitions in titanium alloys. Here the OR peak fitter function is used to determine the OR from alpha-beta boundaries even though they only make up < 1% of all boundaries in the dataset. Advanced plotting functions are employed to produce publication-ready plots.
Example 2 - Parent grain reconstruction in titanium alloys
Example 01: 03 MAR 2021
Parent grain reconstruction and variant analysis in lath martensitic steel
This script follows the same dataset and steps that are used to demonstrate the reconstruction of austenitic parent grains from martensite grains using the grain graph approach in the official MTEX example for martensite transformation in steels. The functionality of ORTools in providing pre-written and additional plotting functions to create publication-ready plots is demonstrated.