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以Zn-25Al-5Mg-2.5Si合金为基体材料,通过常规铸造方法制备了加入不同含量稀土Y的锌铝合金。采用扫描电镜、拉伸试验机、硬度计等分析研究了稀土Y对合金显微组织和力学性能的影响。实验结果表明,添加稀土Y后,在锌铝合金中,其与Al、Zn等元素形成硬度高、热硬性好的复杂成分化合物,分散于晶界和枝晶中,细化了组织,有效地阻碍了高温时基体的变形和晶界移动。随着Y含量的增加,在室温、100℃和180℃时合金的抗拉强度基本呈先升后降的趋势。当Y含量为0.4%(质量分数)时合金的综合性能最好,高温强度和硬度显著提高。180℃时合金的抗拉强度比不加Y时提高了26.4%,硬度提高了47.8%。
Zn-25Al-5Mg-2.5Si alloy as the matrix material, prepared by adding conventional methods of casting rare-earth zinc Y-Zn alloy. The effects of rare earth Y on the microstructure and mechanical properties of the alloy were investigated by scanning electron microscopy, tensile testing machine and hardness tester. The experimental results show that the addition of rare earth Y, the zinc and aluminum alloy, with Al, Zn and other elements to form a high hardness, good thermosetting complex composition compounds, dispersed in the grain boundaries and dendrites, refine the organization, effectively hinder The deformation of the matrix and the grain boundary movement at high temperature. With the increase of Y content, the tensile strength of the alloy initially increases and then decreases at 100 ℃ and 180 ℃. When the content of Y is 0.4% (mass fraction), the comprehensive properties of the alloy are the best, and the strength and hardness at high temperature are remarkably improved. The tensile strength of the alloy increased by 26.4% and the hardness increased by 47.8% when the temperature was 180 ℃.