Mechanical properties and corrosion resistance of Mg–10Gd–2Y–0.5Zr alloy by hot extrusion solid-state recycling

Abstract

A solid-recycled Mg–10Gd–2Y–0.5Zr alloy is fabricated by hot deforming of machined chips and conventional hot extrusion. All the recycled specimens exhibit higher yield strength compared with the extruded reference ingots under the same extrusion condition, which is mainly ascribed to fine-grain size, dispersive distribution of oxide and the second phase of recycled specimens. When extruded at 450°C, the ultimate tensile strength and elongation of solid-recycled specimen are higher than reference specimen. As for the corrosion resistance, the corrosion rate of 450°C solid-recycled specimen is slightly higher than reference specimen extruded at the same condition. The 400 and 450°C recycled specimens are corroded uniformly, which is better than the pitting of reference specimens. In 450°C recycled specimen, the dispersive distribution of oxide induces that the corrosion products could hinder the progress of corrosion effectively. Meanwhile, the second phase precipitates easily concentrate along the grain boundary in the reference specimens. The aggregates of precipitates induce the appearance of pitting and deep etch pits.