Analysis of EBSD Grain Size Measurements Using Microstructure Simulations and a Customizable Pattern Matching Library for Grain Perimeter Estimation

作者：Coutinho Y A; Rooney S C K; Payton E J^*

来源：Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science, 2017, 48A(5): 2375-2395.

DOI：10.1007/s11661-017-4031-z

Grain size data from electron backscatter diffraction (EBSD) maps are often reported as the mean of the circle equivalent diameters of the measured grain areas. Circle equivalent diameters are not directly comparable to the lineal intercept measurements more historically common for grain size characterization in analog optical microscopy. While the value of mean lineal intercept is the same in 2D and 3D for a given probe direction, the mean 2D circle equivalent section diameter is not directly related to any 3D property. Estimation of mean lineal intercept from circle equivalent diameter is usually carried out by again assuming feature circularity, despite the obvious corners that are inherent to grains from the requirements of space filling. A direct conversion between section areas and lineal intercepts can be performed if the grain perimeters are known. In the present work, a novel pattern matching library approach is investigated for measurement of grain perimeters using simulated 2D EBSD maps. The results are compared to alternative approaches for perimeter measurement and assessed with respect to spatial resolution, grain size distribution parameters, and relevant ASTM and ISO measurement standards. The benefits and drawbacks of each approach are discussed. Empirical estimators for conversion between lineal intercept, circle equivalent diameter, and ASTM grain size number are presented.

• 出版日期2017-5