纯锆中间层扩散连接TC4钛合金的接头组织与力学性能

Microstructure and Mechanical Properties of Diffusion Bonded Joint of TC4 Alloy Using Zr Interlayer

摘要:

采用纯Zr中间层实现了TC4钛合金的扩散连接。通过扫描电镜(SEM)、能谱分析(EDS)、X射线衍射(XRD)等方法分析了接头界面的微观组织结构,研究了扩散连接工艺参数对接头界面组织及力学性能的影响规律。结果表明,接头界面处生成了成分均匀连续的钛锆固溶体扩散层,同时扩散层中含有大量板条状的α′-Ti(钛马氏体)相；随着连接温度的升高和保温时间的延长,扩散层的厚度逐渐增加,接头室温抗剪强度呈现出先升高后降低的趋势；当连接温度800℃、保温时间40min、连接压力5MPa时,接头室温抗剪强度最高,达到190MPa。

Abstract:

Reliable diffusion bonding of TC4 alloy was achieved using Zr interlayer. The interfacial microstructure was characterized by scanning electron microscopy(SEM), energy dispersive spectrum analysis(EDS) and X-ray diffraction(XRD). Effects of joining parameters on the microsturcture and mechanical propertie s of the joints were investigated. The results indicated that (Ti,Zr) diffusion layer with uniform components transition was formed at the interface of the joint, in which consisted of a large amount of lath-like α′-Ti(titanium martensite). With the increase of bonding temperature and holding time, the thickness of the diffusion layer increased, and the shear strength of the joint increased until the maximum shear strength was reached and then decreased. The maximum shear strength was 190MPa when the joint was bonded at 800℃ for 40min under 5MPa.