TC11钛合金扩散连接接头组织及力学性能研究

Microstructure and Mechanical Properties of Diffusion Bonded TC11 Alloy Joint

摘要:

研究不同连接温度对TC11合金直接扩散连接接头的显微组织和力学性能的影响,并与原始母材进行了比较。实验结果表明：TC11合金直接扩散连接的最优工艺参数为900 ℃/30 min/60 min,扩散接头界面处无孔洞,接头抗拉强度与原始TC11母材接近且塑性优于原始母材。对原始TC11母材和最优工艺参数下的扩散焊接头在室温下进行高周疲劳性能测试。与原始TC11母材相比,TC11合金直接扩散连接的疲劳性能降低,且所有接头断裂均发生在扩散结合界面处。通过观察疲劳断口结合界面的微观结构特征分析得出,扩散接头界面两侧母材的晶体取向差异使得疲劳裂纹萌生,这是降低接头疲劳性能的主要原因。

Abstract:

The effects of different bonding temperatures on the microstructure and mechanical properties of TC11 alloy diffusion bonded joints were investigated and compared with the original base metal. The experimental results show that the optimal parameter for direct diffusion bonding of TC11 alloy was 900 ℃/30 min/60 min. There are no holes at the interface of the diffusion bonded joint, and the tensile strength of the joint was close to that of the original TC11alloy base metal. In addition, the plasticity of TC11 alloy diffusion bonded joint was better than that of the original base metal. High cycle fatigue properties tests were performed at room temperature for the original TC11 alloy base metal and the diffusion bonded joints under optimal process parameter. Compared with the original TC11 alloy base metal, the fatigue property of the direct diffusion bonding of the TC11 alloy was reduced, and all the diffusion bonded joint fractures occur at the diffusion bonded interface. By observing the microstructural characteristics of the fatigue fracture and interface, it is concluded that the difference in the crystal orientation of the base metal on both sides of the interface of the diffusion joint caused fatigue crack initiation, which is the main reason for reducing the fatigue property of the diffusion bonded joint.