添加中间层的TC2钛合金/321不锈钢真空扩散焊研究

Research on Vacuum Diffusion Welding of TC2 Titanium Alloy/321 Stainless Steel with Intermediate Layer Addition

目的以Cu箔、Ni箔为中间层,使用真空扩散焊工艺实现TC2钛合金与321不锈钢的焊接。方法采用扫描电子显微镜、EDS能谱仪、X射线衍射仪、冲击韧性实验机、显微硬度计等仪器研究了焊接温度、典型中间层材料等工艺参数对TC2钛合金/321不锈钢焊接界面微观结构、界面元素扩散、接头力学性能的影响规律。结果在添加中间层的扩散焊接头中,是否会形成界面区和扩散区以及界面区和扩散区的宽度,受焊接温度的影响,也受中间层和母材成分及性能的影响。在以Ni为中间层的TC2钛合金与321不锈钢真空扩散焊接头中,扩散区会产生AlNi_(3)、NiTi等新物相,当以Cu为中间层时,扩散区中会产生Cu_(0.81)Ni_(0.19)等新物相。在实验条件下,使用铜箔作为中间层的TC2钛合金与321不锈钢真空扩散焊接头的力学性能优于使用镍箔作为中间层的真空扩散焊接头的力学性能。结论在实验条件下,添加中间层的TC2钛合金/321不锈钢真空扩散焊的最佳工艺参数如下:真空度为10^(-4)Pa,焊接温度为820℃,焊接压力为15MPa,焊接时间(即保温时间)为90min,保压时间为240min,以Cu作为中间层。

The work aims to weld TC2 titanium alloy/321 stainless steel by vacuum diffusion welding with Cu foil and foil as the intermediate layers.Instruments such as scanning electron microscope,EDS spectrometer,X-ray diffractometer,im-pact toughness tester,and microhardness tester were employed to investigate the influence of welding temperature,intermediate layers,and other process parameters on the microstructure,interfacial element diffusion,and mechanical properties of the welded joint between TC2 titanium alloy and 321 stainless steel.The results showed that the formation of interfacial and diffu-sion zones,as well as their widths,in the diffusion-welded joints with intermediate layers,were influenced by the welding tem-perature,as well as the composition and properties of the intermediate layer and base materials.In the vacuum diffusion welding of TC2 titanium alloy and 321 stainless steel with Ni as the intermediate layer,phases such as AlNi_(3) and NiTi were formed in the diffusion zone.When Cu was used as the intermediate layer,Cu_(0.81)Ni_(0.19) and other phases emerged in the diffusion zone.Under experimental conditions,the mechanical properties of the vacuum diffusion-welded joint between TC2 titanium alloy and 321 stainless steel with Cu foil as the intermediate layer were superior to those using Ni foil.The optimal process parameters for vacuum diffusion welding of TC2 titanium alloy/321 stainless steel with an intermediate layer under experimental conditions are:vacuum level of 10^(-4) Pa,welding temperature of 820℃,welding pressure of 15 MPa,welding time(i.e.,holding time)of 90 minutes,pressure holding time of 240 min,with Cu as the intermediate layer.