Mechanical Properties of High Mg-Content Al-Mg-Sc-Zr Alloy Fabricated by Selective Laser Melting

Abstract

The effects of process parameters and aging treatment on the microstructure and mechanical properties of selective laser melting (SLM) fabricated high Mg-content Al-Mg-Sc-Zr aluminum alloy were systematically studied. Our experiment results show that the samples exhibit good processability with porosity less than 1%. The increase of Mg content in Al-Mg-Sc-Zr is beneficial to reduce the texture of the alloy. The laser scanning speed has a large influence on the Vickers hardness of as-fabricated samples. The maximum microhardness of as-fabricated sample reaches 148 ± 2 HV with a compression yield strength of 342 ± 7 MPa. After aging treatment, the distinction in microhardness of the samples obtained under different laser scanning speed is obviously reduced, and the mechanical properties of the samples are further improved with a maximum microhardness of 175 ± 5 HV and a maximum compressive yield strength of 476 ± 10 MPa, which are superior to the known Al-Mg-Sc-Zr alloy with same Sc and Zr content fabricated by SLM. In this study, a novel high Mg-content Al-Mg-Sc-Zr aluminum alloy specifically for SLM with good processability and mechanical properties was reported.