Effect of deposition strategy on microstructure and mechanical properties of 5356 aluminum alloy fabricated by arc plasma directed energy deposition

Abstract

Cold metal transfer and pulse (CMT+P) composite arc plasma directed energy deposition (AP-DED) has excellent material utilization, low heat input, minimal distortion and stress, and strong interlayer bonding strength. In this study, three large-size block parts, namely parallel reciprocating scanning (PRS) block part, square crossing scanning (SCS) block part, and interpolat stacking scanning (ISS) block part, were successfully prepared by using this technology. An infrared camera and a high-speed camera were used to study the CMT+P process. The mechanical properties and microstructure of 5356 aluminum alloy block parts have been studied under different deposition strategies. The results reveal a progressive reduction in microhardness from the bottom to the top of the parts fabricated using the three distinct deposition strategies, with the parts by the PRS strategy exhibiting the highest microhardness values. Tensile properties show that the SCS part has the worst anisotropy, the PRS part has the highest tensile properties in the vertical direction, and the ISS part has the highest tensile values in the horizontal direction. Different deposition strategies can be used to prepare parts according to different stress modes.