|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Phase Transformations and Microstructural Evolution
||Quantitative Transmission Electron Microscopy of Microstructure Evolution in Al-Cu Alloys during Laser-induced Rapid Thermal Transients Characteristic of Additive Manufacturing
||Jorg Wiezorek, Kai Zweiacker, Can Liu, Joseph McKeown, Geoffrey Campbell
|On-Site Speaker (Planned)
Microstructures in additive manufacturing derived materials evolve during sequences of micro- to millisecond heating-cooling cycles. The attendant microstructural changes are governed by metallurgical phenomena at sub-micrometer length scales under non-isothermal and non-equilibrium conditions. The initial transient establishes rapid solidification microstructures, which are modified in subsequent thermal cycles by series of solid-state transformations. We posit that interrogation of microstructure evolution in AM materials at the requisite spatiotemporal scales is essential to develop mechanism-informed and accurate processing-microstructure relationships. Here we combined nano-scale spatiotemporal resolution in situ transmission electron microscopy, thermal transport modeling, and post mortem S/TEM analyses by quantitative composition and crystal orientation mapping to study microstructure evolution in pulsed laser induced rapid transformations sequences in Al-rich Al-Cu systems. The TEM experiments and numerical modeling enabled measurements of transformation rates and temperature fields, determination of microstructure evolution and mechanistic insights to non-equilibrium processes responsible for microstructure development under conditions characteristic of AM.
||Planned: Supplemental Proceedings volume