Determining Grain Size from Backscatter Electron Images

Author(s):

Jonathan Ligda

Abstract:

A previous literature report by Bennett and Taleff presented a method of measuring grain size using electron backscatter images; if practical, this method will add a new capability to in-house grain size measurements. Determining the grain size of a material is a critical part of characterization because it is correlated to strength and accurately measuring it typically requires capturing images that show the grain boundaries. For some materials (i.e., ceramics), it is not easy to image the grain boundaries using traditional methods such as optical microscopy. Diffraction-based methods, such as electron backscatter diffraction, are also difficult for some ceramic samples due to either inconsistent or unknown crystal structures. Capturing backscatter electron images is an effective and quick method of imaging grains in many materials; however, there must be a method to quantify the grains from the grayscale images. In this work, the method reported by Bennett and Taleff is used to measure the grain size for silicon carbide to determine the effectiveness for future use.