添加钇对TiAl合金组织和性能的影响

Effects of Y-Addition on Microstructure and Mechanical Properties of TiAl -Base Alloys

设计并熔炼了成分为的合金，用金相显微镜、扫描电镜、三点弯曲试验等手段，研究了添加钇（Ｙ）对ＴｉＡｌ合金显微组织和力学性能的影响。结果表明：钇的添加能改变ＴｉＡｌ合金显微组织，使γＴｉＡ１合金晶粒细化，促进γ＋α２片层状组织的形成。适量钇的添加能降低ＴｉＡｌ合金中Ｏ、Ｎ等间隙原子含量并增加ＴｉＡｌ合金的室温抗弯强度和塑性；当钇的添加量超过其在ＴｉＡｌ合金中的固溶度时，将形成新的Ｔｉ－Ａｌ－Ｙ三元化合物，反而会降低ＴｉＡｌ合金的室温强度和塑性。

Ti_(50)Al_(50))_(100-x)Y_x ternary alloys with various Y content(x(atom)=0～2.0%) were designed and smelt.The effect of Y-addition on microstructure and mechanieal properties of TiAl alloys are investigated by metallography,scanning electron microscope,3-point bending tests and so on.The results show that the Y-addition can change the microstructure of TiAl alloys such as fining the grain size of γTiAl and promoting the formation of γ+α_2 lammellar structure;Y in suitable addition amount can absorb interetitial atoms such as O and N and improve strength and ductility of TiAl alloys at ambient temperature;The strength and ductility of TiAl alloys will decrease because of the formation of new ternary compounds when Y-addition amount exceeds its solid solubility in TiAl alloys.