稀土Gd对Zn-25Al-5Mg-2.5Si合金铸态组织和力学性能的影响

Effect of Rare Earth Gd on the As-cast Microstructure and Mechanical Properties of Zn-25Al-5Mg-2.5Si Alloy

以铸态Zn-25Al-5Mg-2.5Si合金为基体,分析讨论了不同含量的稀土元素Gd对实验合金铸态组织和力学性能的影响。实验结果表明:稀土元素Gd加入合金后使其晶粒明显细化,并在组织中形成了新的稀土相。合金的室温和高温力学性能得到提高,高温性能尤为明显。当Gd添加量为0.8%时,合金的性能最好。100℃和180℃时的抗拉强度与不加稀土时相比分别提高了37.7%和45.6%,而硬度提高了76.9%和78.2%。加入稀土Gd后,实验合金中形成的稀土化合物相是Al3Gd和GdZn12。

The effects of rare element Gd on the as-cast microstructure and mechanical properties of test alloy were investigated based on Zn-25Al-5Mg-2.5Si alloy.The test results show that the grains of alloy are obviously refined and the new rare earth compounds formed with the addition of Gd.While the mechanical properties at room temperature and elevated temperature are improved,especially at elevated temperature.The optimization of microstructure and properties was obtained with 0.8% Gd addition. The alloy can be increased by 37.7% and 45.6% in tensile strength and be increased by 76.9% and 78.2% in hardness at 100 ℃ and 180 ℃,respectively.Rare earth compounds formed in the alloy are Al3 Gd and GdZn12.