|About this Abstract
||2023 TMS Annual Meeting & Exhibition
||Quantifying Microstructure Heterogeneity for Qualification of Additively Manufactured Materials
||Heterogeneous Microstructure and Location-specific Mechanical Performance of Ti-6Al-4V Parts Made by Laser Directed Energy Deposition
||Janelle Hobbs, Xiaochuan Tang, Kaka Ma
|On-Site Speaker (Planned)
Heterogeneity and texture in microstructure have become commonly known phenomena in additively manufactured metals and alloys, due to the transient heat transfer conditions of the layer-by-layer deposition. Particularly, Ti-6Al-4V, a duplex α-β alloy, can exhibit distinctive and varying microstructure at different locations in the printed parts. In the present study, Ti-6Al-4V tubes are made by laser directed energy deposition. The distribution and relative amount of Widmanstätten microstructure and martensitic features are quantified as the location moves from bottom to top along the build direction and from inner wall to outer wall along transverse direction. Location-specific mechanical performance is measured via nanoindentation and nanoscratch. Uncertainty analysis is applied to identify appropriate weighting factors to various laser scanning parameters. Based on those data, we propose a strategy of intra- and inter-layer modification of laser power and hatch parameters with the assistance of in-situ melt pool monitoring to improve microstructural homogeneity.
||Additive Manufacturing, Titanium, Other