Additive friction stir deposition of WE43: The influence of rotation speed on microstructure, mechanical and corrosion properties

Abstract

The additive friction stir deposition (AFSD) process was successfully conducted on WE43 Mg alloy. WE43 buildings under a wide range of heat input condition (rotation speed of print head from 300 rpm to 600 rpm) with four layers were successfully prepared using AFSD. The comprehensive relationship between the heat input and microstructure-mechanical-corrosion properties was revealed through scanning electron microscopy, electron back-scattered diffraction, X-ray diffraction, tensile testing, electrochemical testing and immersion testing. After AFSD, the average grain size reduced from ∼87 μm to <5 μm. Results of tensile test indicated that samples at 350 rpm exhibited the best comprehensive mechanical properties with the yield strength, ultimate tensile strength and elongation were 216.1 ± 1.9 MPa, 242.6 ± 2.3 MPa and 10.6 ± 1.9 %, respectively. Regardless of heat input, a relatively dense corrosion product was formed on the surface of AFSD samples during immersion. The findings of this work attempted to provided theoretical and practical foundations to guide the parameter-microstructure-performance connection of high-performance Mg-based alloys fabricated by AFSD.