The microstructure of Mg-8Zn-4Al-1Ca aged alloy was investigated by TEM and HRTEM. The results show that the hardening produced in the Mg-8Zn-4Al-1Ca alloy is considerably higher than that in the Mg-8Zn-4A1 alloy. A d...The microstructure of Mg-8Zn-4Al-1Ca aged alloy was investigated by TEM and HRTEM. The results show that the hardening produced in the Mg-8Zn-4Al-1Ca alloy is considerably higher than that in the Mg-8Zn-4A1 alloy. A dense dispersion of disc-like Ca2Mg6Zn3 precipitates are formed in Mg-8Zn-4Al-1Ca alloy aged at 160 ℃ for 16 h. In addition, the lattice distortions, honeycomb-looking Moir＆#233; fringes, edge dislocations and dislocation loop also exist in the microstructure. The precipitates of alloy aged at 160 ℃ for 48 h are coarse disc-like and fine dispersed grainy. When the alloy is subjected to aging at 160 ℃ for 227 h, the microstructure consists of numerous MgZn2 precipitates and Ca2Mg6Zn3 precipitates. All the analyses show that Ca is a particularly effective trace addition in improving the age-hardening and postponing the formation of MgZn2 precipitates in Mg-8Zn-4Al alloy aged at 160 ℃.展开更多
为了研究等温锻造温度对机械外壳用Mg-8Al-1Zn-0.5Ca镁合金组织与性能的影响,选择5种等温锻造温度对合金试样进行锻造试验,并进行了显微组织分析、耐腐蚀和耐磨损性能的测试与分析。结果发现:随着等温锻造温度从340℃增加至420℃,Mg-8Al...为了研究等温锻造温度对机械外壳用Mg-8Al-1Zn-0.5Ca镁合金组织与性能的影响,选择5种等温锻造温度对合金试样进行锻造试验,并进行了显微组织分析、耐腐蚀和耐磨损性能的测试与分析。结果发现:随着等温锻造温度从340℃增加至420℃,Mg-8Al-1Zn-0.5Ca镁合金的平均晶粒尺寸先减小后增大、腐蚀电位先正移后负移、磨损体积先减小后增大,合金的耐腐蚀和耐磨损性能先变好后变差。相较于等温锻造温度为340℃,等温锻造温度为400℃时的Mg-8Al-1Zn-0.5Ca镁合金的平均晶粒尺寸减小了76.1%、腐蚀电位正移141 m V、磨损体积减小了66.2%。研究结果表明,Mg-8Al-1Zn-0.5Ca镁合金的等温锻造温度优选为400℃。展开更多
基金Project(51141007)supported by the National Natural Science Foundation of ChinaProject(E2013501096)supported by Hebei Province Natural Science Foundation,China
文摘The microstructure of Mg-8Zn-4Al-1Ca aged alloy was investigated by TEM and HRTEM. The results show that the hardening produced in the Mg-8Zn-4Al-1Ca alloy is considerably higher than that in the Mg-8Zn-4A1 alloy. A dense dispersion of disc-like Ca2Mg6Zn3 precipitates are formed in Mg-8Zn-4Al-1Ca alloy aged at 160 ℃ for 16 h. In addition, the lattice distortions, honeycomb-looking Moir＆#233; fringes, edge dislocations and dislocation loop also exist in the microstructure. The precipitates of alloy aged at 160 ℃ for 48 h are coarse disc-like and fine dispersed grainy. When the alloy is subjected to aging at 160 ℃ for 227 h, the microstructure consists of numerous MgZn2 precipitates and Ca2Mg6Zn3 precipitates. All the analyses show that Ca is a particularly effective trace addition in improving the age-hardening and postponing the formation of MgZn2 precipitates in Mg-8Zn-4Al alloy aged at 160 ℃.
文摘为了研究等温锻造温度对机械外壳用Mg-8Al-1Zn-0.5Ca镁合金组织与性能的影响,选择5种等温锻造温度对合金试样进行锻造试验,并进行了显微组织分析、耐腐蚀和耐磨损性能的测试与分析。结果发现:随着等温锻造温度从340℃增加至420℃,Mg-8Al-1Zn-0.5Ca镁合金的平均晶粒尺寸先减小后增大、腐蚀电位先正移后负移、磨损体积先减小后增大,合金的耐腐蚀和耐磨损性能先变好后变差。相较于等温锻造温度为340℃,等温锻造温度为400℃时的Mg-8Al-1Zn-0.5Ca镁合金的平均晶粒尺寸减小了76.1%、腐蚀电位正移141 m V、磨损体积减小了66.2%。研究结果表明,Mg-8Al-1Zn-0.5Ca镁合金的等温锻造温度优选为400℃。
