Effect of microwave post-process heat treatment on the microstructure of wire-arc additively manufactured Mg alloy

Abstract

Microwave hybrid heating is proposed as a novel post processing technique to achieve homogeneous microstructure in wire arc direct energy deposited AZ31 Mg alloy (DED-Arc/AZ31). Non-uniform microstructure in the build direction owing to the prevailing thermal history during DED-Arc process is a major drawback. Microwave molecular interaction results in rapid volumetric heating and restricts the microstructural coarsening owing to thermodynamic grain boundary pinning. Homogeneous grain size distribution was achieved through the post processing, and uniform microhardness could be observed from bottom to top layer.