Automated 3D EBSD for metallic powders

Caitlin Walde, Roger Ristau, Danielle Cote

Metallic powders are commonly used in additive manufacturing processes. While their post-process consolidated properties are widely studied, there is little research on the properties of the powders prior to consolidation. Understanding the powder characteristics before use in additive manufacturing processes could lead to fine-tuning properties of additively manufactured materials. The three-dimensional grain structure of metals can be useful in predicting their properties and microstructure. Powder particles are much smaller and more difficult to fixture and polish than their bulk counterparts, hence typical protocols are difficult to use when serially sectioning them. This method describes a recommendation as to how to fixture, mill, and image metallic powder particles using a Xe P-FIB to mill and take EBSD measurements. It is based on milling and imaging techniques used for bulk materials, but with the specific advantage of how to fixture the powder sample. Our modifications include: the method of fixturing the specimen to the holder; the method of protecting the sample during milling.