Mechanical properties of Mg-9Gd-4Y-0.6Zr alloy
(1.School of Materials Science and Engineering, Central South University, Changsha 410083, China
2.湖南省长沙市中南大学材料科学与工程学院)
2.湖南省长沙市中南大学材料科学与工程学院)
Abstract: The microstructures and mechanical properties of Mg-9Gd-4Y-0.6Zr alloy were investigated. The results show that the ultimate tensile strengths of the extrusion-T5 temper of this alloy at -196, 25, 250, 300 and 350 ℃ are as high as 521, 370, 348, 262 and 150 MPa, respectively. It is noteworthy that 8% plasticity occurs at -196 ℃ and 180% superplasticity occurs at 400 ℃. In the peak hardness of Cast-T5, Cast-T6, Ext-T5 and Ext-T6, the highest is that of Ext-T5. The prismatic precipitates providing an effective barrier to dislocation gliding on the basal plane are the cause of strengthening of this alloy. The plate-shaped precipitates formed on the prismatic planes provide the most effective barriers to the gliding dislocations, and they are the cause of strengthening of this alloy.
Key words: Mg-Gd-Y-Zr alloy; rare earth element; heat resistance; mechanical properties