TC4钛合金扩散焊接头的力学性能

在温度为910℃，压力为3.4MPa条件下对TC4钛合金板材进行了扩散焊接，对获得的扩散焊接头取样进行金相观察，仅在接近接头表面材料深度为1mm范围内发现未焊合缺陷，其余部分焊合较好，表明在给定工艺下可获得质量良好的焊接头.随后对TC4扩散焊接头的力学性能进行了试验研究，分别开展了静拉伸试验、断裂韧性试验及焊缝附近区域的纳米压痕试验.试验结果表明，所制得的TC4扩散焊接头屈服强度为887MPa，抗拉强度为948MPa，断裂韧性为101.9MPa·m1/2，均与原材料的性能相差不大.纳米压痕试验的结果显示，接头焊缝区和母材区的显微弹性模量分别为180.2GPa和178.0GPa. 

Mechanical properties of TC4 titanium alloy diffusion bonded joints

The diffusion bonding of TC4 titanium alloy plate was conducted under the condition of 910 ℃ temperature and 3.4 MPa pressure.Specimens were cut from the gained joints to conduct metallographic analysis.It indicated that the sound joints can be achieved under selected process parameters,since several microscopic defect only existed within the depth of 1 mm from the surface of the joints.Subsequently,the mechanical properties of diffusion bonded joints were studied.The static tensile test,fracture toughness test and nano indentation test were carried out for diffusion bonded joints.The results show that the yield strength of the gained diffusion bonded joints is 887MPa,its tensile strength is 948MPa and fracture toughness is 101.9 MPa · m1/2,presenting little difference of properties with raw materials.The results of nano indentation tests indicate that the micro elastic modulus of the bond line and the based metal region are 180.2 GPa and 178.0 GPa respectively.