(華南理工大學(xué) 材料學(xué)院, 廣州 510640)
摘 要: 利用金相、 掃描電鏡觀察及能譜分析研究了Ti、 Al及Al-RE合金作為細化劑對Zn-2Ni合金中Zn-Ni金屬間化合物的細化效果。 結(jié)果表明： 在Zn-2Ni合金中加入微量（≤0.20%）的Ti、 Al及Al-RE均可對合金凝固組織中的金屬間化合物粒子產(chǎn)生細化作用； 以Ti為細化劑時，組織中會出現(xiàn)較大的ZnNiTi三元板條狀粒子； 以純Al為細化劑時， 出現(xiàn)δ-NiZn8相依附γ-Ni2Zn5相生長的大粒子和以枝晶狀NiAl相為核心較細小的δ-NiZn8相粒子共存于凝固組織中；以Al-RE為細化劑時， 將獲得分布均勻且細化的γNi2Zn5相粒子，且Al-RE合金細化效果明顯優(yōu)于Ti和Al， 其最佳的加入濃度為0.05%～0.10%。
關(guān)鍵字: Zn-Ni合金； 細化； 金屬間化合物
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
