Effects of heat treatments on microstructure and mechanical properties of Mg–11Y–5Gd–2Zn–0.5Zr (wt.%) alloy

摘要: Abstract The microstructure and mechanical properties of Mg–11Y–5Gd–2Zn–0.5Zr (wt.%) (WGZ1152) alloy during different heat treatments were investigated. Almost all the Mg 24 (GdYZn) 5 eutectic phases dissolved into α-Mg matrix after solution treatment at 535 °C for 20 h. After ageing 225 °C 24 h (T6 state), a great amount fine β′ precipitates formed. Both 18R-type long period stacking ordered (LPSO) 12 YZn phase 6H′-type LPSO exhibit good thermal stability high-temperature process. are much harder than have volume fraction ∼16%. ultimate tensile strength room temperature peak-aged state) is 307 ± 6 MPa elongation 1.4 ± 0.3%. in T6 state shows anomalous positive dependence from to 250 °C, maintains more 260 MPa up 300 °C (0.64 T m ). excellent WGZ1152 both elevated temperatures mainly attributed solid strengthening, strengthening strengthening. Slip line observations suggest transition basal non-basal slip with increasing temperature.