|About this Abstract
||MS&T23: Materials Science & Technology
||Phase Transformations and Microstructure Evolution during Post-Processing of Additively Manufactured Metals
||Use of In Situ TEM Heating to Study Transformation Pathways for Metastable Phases in New Candidate Alloys for Additive Manufacturing
||Mingxuan Li, Baris Yavas, Mark Aindow
|On-Site Speaker (Planned)
Laser glazing of solid alloy substrates in powder bed fusion machines is an efficient way to perform an initial screening of candidate alloys for metal additive manufacturing. Recently we have applied this approach to evaluate two types of quasicrystal-reinforced aluminum alloys. Since the quasicrystal phases are inherently metastable, it is important to understand the transformations that may occur in such alloys during the build cycle and/or during post-build heat-treatment. Forensic analysis of the as-built and heat-treated microstructures provides useful information about the phases present in these conditions, but does not capture either the kinetics or the details of the transformation pathways. These aspects can be explored by in situ transmission electron microscopy heating studies on samples prepared by focused ion beam milling. Here we present examples of such studies on phase stability in laser-glazed quasicrystal-reinforced aluminum alloys, and the implications for use of these alloys in additive manufacturing are discussed.