Rapid defect prediction and optimisation method for Ti-modified AlCuMg alloys processed by laser powder-bed fusion

Ti-modified AlCuMg alloys have demonstrated great potential in improving the printability and mechanical properties of conventional Al alloys processed by laser powder-bed fusion (LPBF). However, an effective material design method, which considers processing parameters and solidification microstructure, is currently absent. Accordingly, the present work proposed a comprehensive model with which the formation of hot-tearing cracks and lack-of-fusion pores could be more efficiently predicted. The hot-tearing factor was an assistant in the tailoring of crack-free Ti-modified AlCuMg alloys, while the lack-of-fusion factor suggested a volumetric energy density for better printability. This hot-tearing factor could also serve as the supplementary method for evaluating the crack susceptibility of AlCuMg alloys. The microstructure evolution and mechanical properties were also investigated to achieve an optimal processing window for these alloys, which could satisfy the dual requirements of higher mechanical properties and better formability. It was believed that this comprehensive model would facilitate the tailoring of crack-free AlCuMg alloys and the optimisation of processing parameters in a time-efficient manner with high precision.