(华南理工大学 材料学院, 广州 510640)
摘 要: 利用金相、 扫描电镜观察及能谱分析研究了Ti、 Al及Al-RE合金作为细化剂对Zn-2Ni合金中Zn-Ni金属间化合物的细化效果。 结果表明： 在Zn-2Ni合金中加入微量（≤0.20%）的Ti、 Al及Al-RE均可对合金凝固组织中的金属间化合物粒子产生细化作用； 以Ti为细化剂时，组织中会出现较大的ZnNiTi三元板条状粒子； 以纯Al为细化剂时， 出现δ-NiZn8相依附γ-Ni2Zn5相生长的大粒子和以枝晶状NiAl相为核心较细小的δ-NiZn8相粒子共存于凝固组织中；以Al-RE为细化剂时， 将获得分布均匀且细化的γNi2Zn5相粒子，且Al-RE合金细化效果明显优于Ti和Al， 其最佳的加入浓度为0.05%～0.10%。
关键字: Zn-Ni合金； 细化； 金属间化合物
Zn-2Ni alloy
（ School of Materials Science and Engineering,
South China University of Technology, Guangzhou 510640, China）
Abstract: The refining effects of Ti, Al and Al-RE alloy on intermetallic compounds in Zn-2Ni alloy were studied by optical microscopy, scanning electro microscopy (SEM) and energy dispersive spectrometer (EDS). The results show that adding a small amount of (≤0.20%)Ti, Al and Al-RE alloy into Zn-2Ni alloy can refine the intermetallic compounds particles. The big Zn-Ni-Ti plate particles occur in the alloy when using Ti as refiner. The big particles grown by δ-NiZn8 on γ-Ni2Zn5 and small δ-NiZn8 particles nucleated on the surface of NiAl phase co-exist in the solidification structures of alloy when using Al as refiner. The uniform alloy distributing and refined γ-Ni2Zn5 particles form when using Al-RE as refiner. The refining effect of Al-RE is better than pure Al and Ti in Zn-Ni master alloy, and the optimized concentration of Al-RE in the melt is 0.05%-0.10%.
Key words: Zn-Ni alloy; refinement; intermetallic compounds
