Selective laser melting of Al–8.5Fe–1.3V–1.7Si alloy: Investigation on the resultant microstructure and hardness

This article presents the microstructure and hardness variation of an Al–8.5Fe–1.3V–1.7Si (wt%, FVS0812) alloy after selective laser melting (SLM) modification. Three zones were distinguished across the melting pool of the SLM-processed FVS0812 alloy: the laser melted zone (LMZ), the melting pool border, and the heat affected zone (HAZ) in the previously deposited area around the melting pool. Inside the LMZ, either an extremely fine cellular-dendritic structure or a mixture zone of the α-Al matrix and nanoscale Al12(Fe,V)3Si particles appeared. With a decreased laser beam scanning speed, the cellular-dendritic structure zone within the LMZ shrank significantly while the mixture zone expanded. The α-Al and Al12(Fe,V)3Si mixture zone was also observed in the HAZ, but another phase, submicron θ-Al13Fe4 particles with rectangular or hexagonal shapes, formed along the melting pool border. Microhardness tests indicated that the hardness of the SLM-processed FVS0812 samples far exceeded that of the as-cast FVS0812 alloy.