Evolution of microstructure of WE43 magnesium alloys fabricated by laser deposition manufacturing with subsequent friction stir processing

摘要

? 2022 Elsevier B.V.WE43 magnesium alloy fabricated by laser deposition manufacturing (LDM) has broad application prospects in aerospace fields. In this paper, the friction stir processing (FSP) of the deposited zone (DZ) is used to improve the microstructure and eliminate pore defects of the LDMed WE43 alloy. In the DZ, the matrix phase is α-Mg with Zr-rich phases inside, and the inter-dendritic eutectic structure is composed of Mg12Nd and Mg24Y5 phases. After FSP, the inter-dendritic eutectic structure was broken, and the Zr-rich phases were finer and diffusely distributed in the α-Mg matrix; the porosity was decreased from 1.4% in the DZ to 0.04%. The grain size was reduced by 86% compared to the DZ, which promotes the increase of microhardness.