Microstructure heterogeneity and mechanical properties of Mg-Gd-Y-Zr alloy fabricated by force-controlled additive friction stir deposition

Multi-layer single-pass deposits of high-performance Mg-8Gd-3Y-0.5Zr alloy were successfully prepared using force-controlled additive friction stir deposition (AFSD) with a high deposition rate. The microstructure and mechanical properties heterogeneity along the build direction and transverse direction of the final deposits were investigated. The grain size of the coarse grain zone (CGZ) formed on advancing side (AS) is roughly 11–17 μm, two to three times larger than that of the other regions. Because of the evident grain refinement during deposition, the tensile properties in the center and retreating side (RS) regions of as-deposited final deposits are superior to those of the extruded Mg-8Gd-3Y-0.5Zr alloy.