电弧熔炼态NiAl-V合金的组织演变与力学性能

Microstructure and Properties of NiAl-V Alloy Prepared by Arc Melting

摘要:

采用真空电弧熔炼制备了Ni-34Al-32V(at.%)及Ni-28.5Al-43V(at.%)成分的合金。对于真空电弧熔炼纽扣锭不同位置处微观组织及力学性能进行了研究。利用光学显微镜（OM），X射线衍射（XRD），扫描电镜（SEM） 分析了合金不同凝固位置处的相组成和组织形态, 结果表明，32V合金的凝固组织由NiAl初生枝晶及NiAl+V片层共晶组成；43V合金的凝固组织由V初生枝晶与NiAl+V片层共晶共同组成。同时对合金进行了力学性能测试，高温压缩强度与室温断裂韧性较NiAl合金均有很大提高，表明V的加入可提高NiAl合金的室温断裂韧性与高温强度。

关键词:Ni-Al-V三元合金;初生枝晶;断裂韧性;压缩性能

Abstract:

The ternary alloy of Ni-34Al-32V(at%) and Ni-28.5Al-43V were prepared with success by vacuum non-consumable arc melting.The various locations of alloy solidified microstructure and compression behavior were investigated by using optical microscope(OM), X-ray diffraction(XRD) as well as scanning electron microscope (SEM).The results show that the solidified microstructure of the ternary alloy NiAl-32V was mainlly composed of the NiAl primary phases and NiAl+V eutectic.Meanswhile, the NiAl-43V was mainlly composed of the V primary phases and NiAl+V eutectic.At the same time, the mechanical properties of these two alloys were tested.From the fact, the compressive properties at room and elevated temperatures of the two composites are much higher than those of NiAl alloy.According the fact that V additions can remarkably improve the room-temperature fracture toughness and the elevated temperature strength of the NiAl-V alloy.

Key words:Ni-Al-V ternary alloy; Primary dendritic; Fracture toughness;Compressive properties