Microstructure, texture and mechanical properties in an as-cast AZ61 Mg alloy during multi-directional impact forging and subsequent heat treatment

摘要: Abstract Multi-directional impact forging (MDIF) and subsequent heat treatment were applied to an as-cast AZ61 Mg alloy the microstructure, texture evolution mechanical properties systematically investigated. The microstructural during MDIF was classified into twinning-active dynamic recrystallization (DRX)-predominant stages. During early passes, a complicated twinning behavior observed, including {10–12} primary, {10–12}–{10–12} secondary {10–12}–{10–12}–{10–12} ternary twins with various twin variants, even detwinning behavior. With further continuous forging, disappeared leading formation of coarse DRXed grains, fine grains began nucleate at serrated grain boundaries due discontinuous DRX mechanism progressively consumed eventually resulting in bimodal microstructure. Meanwhile, random turned special non-basal texture. After 400 °C for 2 h, eutectic network completely β-Mg17Al12 particles uniformly locating stayed stable, thereby good balance strength (ultimate tensile 259 MPa) ductility (20.6%).