Developing a best practice for sample preparation of additive manufactured AlSi10Mg for electron backscatter diffraction analysis

Microstructural characterization has a key role in analyzing the properties of additive manufactured materials. Electron backscatter diffraction (EBSD) can offer a unique set of information on the microstructural state of these materials. However, EBSD analyses is extremely sensitive to the quality of the prepared sample and requires a seamless preparation eliminating any risk of contamination, oxidation or surface imperfections. Despite the wide use of EBSD analysis in AM, there is no universally accepted sample preparation protocol and the variety and sequence of the steps that can guarantee high quality data remain unclear. In this study, the efficiency of sample preparation methods with various final steps of vibrational polishing, vibrational polishing + cleaning, vibrational polishing + electro-chemical polishing and vibrational polishing + chemical etching was surveyed and compared for EBSD analyses of notched AM AlSi10Mg part. The obtained results help selecting the most efficient approach indicating that vibrational polishing + chemical etching with hit rate of 95.41% lead to the lowest zero solutions followed by vibrational polishing + electro-chemical polishing, vibrational polishing + pad cleaning and just vibrational polishing, respectively.