热处理温度对Ti_(85)Nb_(10)Sn_(5)合金微观组织及力学性能的影响

Effect of heat treatment temperature on microstructure and mechanical properties of Ti_(85)Nb_(10)Sn_(5)alloy

采用X射线衍射仪、光学显微镜、电子万能试验机、维氏硬度计以及纳米压痕仪等研究了Ti_(85)Nb_(10)Sn_(5)合金经不同温度热处理后的显微组织和力学性能。结果表明:773 K热处理后,合金中的α-Ti相和Ti_(3)Sn相的体积分数分别为79.0%和21.0%,而873 K和973 K热处理后,α-Ti相的体积分数分别为95.8%和98.9%,Ti_(3)Sn相的体积分数分别为4.2%和1.1%。经873 K和973 K热处理后,合金具有较大的塑性变形、较高的维氏硬度和较大的弹性能。973 K热处理后,合金的约化弹性模量(E_(r))为44.0 GPa,与人体骨骼的弹性模量(10~30 GPa)接近,此时合金还具有较大的H/E_(r)和H^(3)/E_(r)^(2)值,表明合金具有较高的耐磨性和抗磨性。因此,具有较高弹性能和较低约化弹性模量的973 K热处理合金是一种实用价值较高的硬组织植入物材料。

Microstructure and mechanical properties of Ti_(85)Nb_(10)Sn_(5)alloy after heat treatment at different temperatures were investigated by means of X-ray diffractometer,optical microscope,electronic universal testing machine,Vickers hardness tester and nano-indentation instrument.The results show that the volume fractions ofα-Ti phase and Ti_(3)Sn phase of the alloy after heat treatment at 773 K are 79.0%and 21.0%respectively,while after heat treatment at 873 K and 973 K,the volume fraction of theα-Ti phase is 95.8%and 98.9%,and the volume fraction of the Ti_(3)Sn phase is 4.2%and 1.1%,respectively.After heat treatment at 873 K and 973 K,the alloy has large plastic deformation,high Vickers hardness and large elastic energy.The reduced elastic modulus(E_(r))of the alloy after heat treatment at 973 K is 44.0 GPa,which is close to the elastic modulus of human bone(10-30 GPa).At this time,the alloy also has large H/E_(r) and H^(3)/E_(r)^(2) values,indicating that the alloy has high wear resistance and anti-wear ability.Therefore,973 K heat-treated alloy with high elastic energy and low reduced elastic modulus is a kind of hard tissue implant material with high medical value.