热处理对Mg-8Gd-3Y-0.5Zr合金组织和力学性能的影响

Effect of Heat Treatment on Microstructure and Mechanical Properties of Mg-8Gd-3Y-Zr Magnesium Alloy

采用光学显微镜、扫描电镜、透射电镜、室温力学测试、硬度测试等方法,研究了不同热处理工艺对Mg-8Gd-3Y-0.5Zr合金显微组织和力学性能的影响.结果表明,均匀化退火能有效消除枝晶偏析、改善材料的组织和力学性能,δ提高30%;挤压可以明显改善合金的强度和塑性,相比铸态,σb提高,48%,σs提高36%,δ达到6.3%;时效可使挤压态合金的强度得到进一步提高,峰时效时,σb、σs分别达到385.6MPa、310.8MPa,但塑性有所降低,δ降低至4.1%.

The effects of heat-treatment conditions on the microstructures and mechanical properties of Mg- 8Gd-3Y-0.5Zr magnesium alloy are investigated by optical microscopy, scanning electron microscopy, trans- mission electron microscopy,tensile test and hardness measurement,etc. The results show that after ho- mogenizing annealing,dendritic segregation is almost eliminated and the microstructures and properties, of alloy are improved;homogenizing annealing can increases 8 about 30 % ; the extrusion can improve the me- chanical properties. Compared with the alloy as-cast, the δb, δ5 increases 48%, and 36%. respectivelyt and the δ can achieve 6.3% ; the aging after extrusion can obviously improve the strength;the δb、δ5a- chieves 385.6 MPa and 310. 8MPa respectively, but 8 is decreased 4.1%.