中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 21 No. 2 February 2011 |
Mg-Zn-Y-Zr alloy prepared by solid state recycling
(1. Southwest Technique and Engineering Institute, Chongqing 400039, China;
2. Chongqing Institute of Coal Science Research Institute, Chongqing 400039, China)
Abstract:Machined chips of Mg-Zn-Y-Zr alloy were consolidated by cold pressing and then hot extrusion under various processing temperatures and extrusion ratios. The results show that the microstructure of the chip-extruded alloy is marked by a large number of recrystallized grains and some unrecrystallized grains, which results in high strength but low ductility at temperatures below 320 °C. With increasing processing temperature up to 360 °C, entirely recrystallized and equiaxed grains are obtained. Mg-Zn-Y-Zr alloy with low strength but high ductility is obtained compared with the alloy processed at low temperature. At 420 °C, coarse and equiaxed grains are formed, which results in the drastic decrease of mechanical properties. With increasing extrusion ratio from 8 to 16, the grain refinement is more obvious and the mechanical properties at room temperature are improved effectively. However, the yield strength and ultimate tensile strength are improved a little with further increasing extrusion ratio.
Key words: Mg-Zn-Y-Zr alloy; extrusion ratio; solid state recycling; processing temperature