| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
2024 Undergraduate Student Poster Contest
|
| Presentation Title |
SPU-23: On the Sources of Discrepancies between EBSD, SEM, and Optical Grain Size Measurements |
| Author(s) |
Darrah Meiyan Timberlake, Kayla S Evans, Priam Tyagi, Victoria Mayne Miller, Eric J Payton |
| On-Site Speaker (Planned) |
Darrah Meiyan Timberlake |
| Abstract Scope |
Despite long-standing standards for measuring grain size, discrepancies persist when comparing optical microscopy, scanning electron microscopy, and electron backscatter diffraction (EBSD) techniques which complicate efforts to develop reliable microstructure-property relationships. This work systematically investigates the sources of these discrepancies using simulated measurements on computationally generated 3D synthetic microstructures with varying grain size distributions. MATLAB scripts utilizing the MTEX toolbox automate the planimetric (Saltikov, Jeffries) and lineal intercept (Heyn, Hilliard, Abrams) measurement methods from ASTM E 112 and E 2627 standards on 2D slices extracted from the synthetic volumes. Effects of grain clustering algorithms, cleanup routines, and number of measurements were explored. The findings provide evidence of a small but systematic discrepancy that exists between planimetric and lineal intercept-based approaches. To improve grain size measurement reproducibility, a new empirical relationship between the ASTM grain size number G and lineal intercepts is proposed. |