A Comparison between Anodizing and EBSD Techniques for Primary Particle Size Measurement

Shahrooz Nafisi,Reza Ghomashchi,George Vander Voort,Anthony Roccisano

doi:10.3390/met9050488

Shahrooz Nafisi, Reza Ghomashchi + Show 2 more

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https://doi.org/10.3390/met9050488

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Abstract

Proper understanding and knowledge of primary particle or grain size is of paramount importance in manufacturing processes as it directly affects various properties including mechanical behavior. Application of optical microscopy coupled with etching techniques has been used conventionally and in conjunction with color metallography (polarized microscopy) has been the preferred method for grain size measurement. An advanced technique as an alternative to light microscopy is using electron backscatter diffraction (EBSD). A comparison is made between these two techniques using Al-7Si alloy produced with various casting techniques to highlight the cost and time of the sample preparation and analysis for both techniques. Results showed that color metallography is certainly a faster technique with great accuracy and a much cheaper alternative in comparison with EBSD.

Highlights

Grain size plays an important role on the properties of metallic materials
Dendrite size had a great difference since the cooling rate is higher in the copper mold (Figure 2c,d)
In order to study the capability of color metallography as a reliable microstructural characterization technique in distinguishing the primary particles, anodizing-polarized light microscopy was compared with the electron backscatter diffraction (EBSD) technique for Al–Si samples produced with different casting procedures; 1

Summary

Introduction

Grain size plays an important role on the properties of metallic materials. The structure is observed on the plane of the polished surface using optical microscopy which is a two-dimensional (2D) measurement. The 2D analysis is not a complete representative of the 3D structure and in some instances may lead to a biased conclusion. It is the current practice for microstructural characterization and there is an urge to ensure the procedure is as effective and accurate as possible. The secondary dendritic branches are treated as individual and isolated particles during automatic image analysis processing [1]

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