|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Additive Manufacturing of Metals: Applications of Solidification Fundamentals
||Understanding Solidification of Al-Alloys Processed by Laser Powder Bed Fusion Additive Manufacturing
||Holden Hyer, Le Zhou, Abhishek Mehta, Sharon Park, Thinh Huynh, Shutao Song, Kyu Cho, Brandon McWilliams, Yongho Sohn
|On-Site Speaker (Planned)
Understanding the process-structure-property relationship in laser powder bed fusion (LPBF) through solidification fundamentals can provide foundational framework for AM-specific alloy/component design with application-tailored properties and desensitized process variability. In this study, six binary Al-Si alloys whose compositions were strategically chosen at hypo-, near-, and hyper-eutectic, were gas atomized into alloy powders, and produced into additively manufactured cubes and tensile bars via LPBF. For each alloy composition, variation in laser power and scan speed was carried out to examine the development of characteristic features such as porosity, solidification cracks, and microstructure. All compositions were produced to 99% density, but alloys with 1 and 2 wt.% Si exhibited cracking, regardless the LPBF parameters employed. Mechanical properties in quasi-static tension were determined and correlated to the Si concentration and microstructural flaws. Experimentally quantified characteristics of melt pools, sub-grain cells, and solidification cracks were employed to corroborate thermal gradient, cooling rates, and Scheil-Gulliver model.