Effect of Heat Treatment on Mechanical Properties of Al-Cu-TiB₂ Alloy Fabricated by Selective Laser Melting

Abstract

This study examined the microstructures and mechanical properties of Al-Cu-TiB₂ alloy fabricated by selective laser melting (SLM). The SLM specimens without solidification cracks were obtained by optimizing laser irradiation conditions, and the relative density was 99.8%. The SLM specimens had a fine solidification structure with equiaxed cells owing to the heterogeneous nucleation by TiB₂ particles. The generation of the solidification cracks was thus suppressed due to dispersed shrinkage strain. The hardness of the SLM specimens increased by the solution treatment and subsequent artificial aging treatment. As a result of the precipitation of an Al₂Cu phase by aging, the SLM specimens have exhibited excellent strength through precipitation hardening.