Early Career Researcher: Student (poster and 2-minute poster pitch) at Digital Twin Symposium 2019, presented by M. G. Rashed
The versatility and easiness of producing complex geometrical forms by additive manufacturing, namely Powder-Bed Fusion (PBF) technique, compared to traditional manufacturing methods has triggered the resurgence of interest in metallic microlattice materials for achieving structural light-weightiness, albeit at the cost of having microstructural heterogeneity and discontinuity in as-built parts due to complex thermo-mechanical process in the melt pool. Built parameters optimized 316L stainless steel microlattice structures with low relative densities were manufactured using Laser-PBF or Selective Laser Melting (SLM) process and the resulting defects were characterized using various advanced microscopy techniques. It was observed that the rapid solidification originated coincidental dislocation network and cellular substructure provide high yield stress, and enhanced twinning accompanied by dynamic recrystallization (CDRX) at high stress overcome the strength–ductility trade-off that counter balance the deleterious effect on structural performance by inherent voids. As a result, the compound response of 316L stainless steel microlattice structures manufactured by SLM process becomes stiffer and stronger than what it would have been by conventional manufacturing methods, rendering the above research outcome of high interest that would help shape the development of next generation high performance alloys and ultra-lightweight structures. By creating a Digital Twin (simulation) of manufacturing, the
process can be optimized and the
microstructure can be controlled,
with custom strength and
ductility achieved for specific
application use cases. Furthermore, the knowledge gained from detailed study of the Digital Twin can be applied to additive manufacturing of other structural alloys.