Microstructures and mechanical properties of Ti₃Al/Ni-based superalloy joints diffusion bonded with Ni and TiNiNb foils

详细信息    查看全文

• 作者：H. S. Ren ; X. Wu ; B. Chen ; H. P. Xiong ; Y. Y. Cheng
• 关键词：(IIW Thesaurus)Diffusion bonding ; Microstructure ; Mechanical properties
• 刊名：Welding in the World
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：61
• 期：2
• 页码：375-381
• 全文大小：
• 刊物主题：Metallic Materials; Continuum Mechanics and Mechanics of Materials; Theoretical and Applied Mechanics;
• 出版者：Springer Berlin Heidelberg
• ISSN：1878-6669
• 卷排序：61

文摘

Dissimilar joining of Ti₃Al-based alloy to Ni-based superalloy has been conducted with diffusion bonding method using Ni foil and TiNiNb alloy as interlayer. For the Ni foil, with the increase of bonding temperature, the joint strength increased firstly and then decreased. The joints bonded at 980 °C for 20 min with a pressure of 20 MPa presented the maximum shear strength of 207 MPa at room-temperature. During the bonding process, Ni foil reacted with Ti₃Al-based alloy due to the strong affinity between elements Ti and Ni. The formation of Ni₂Ti, AlNi₂Ti, and Ni₃Ti compounds at Ti₃Al/Ni interface limited the mechanical properties of the joint. The use of the TiNiNb alloy decreased the formation tendency of brittle Ti-Ni phases to some extent and only little Ti₂Ni phase was visible in the joint. The shear strength of 209 MPa was obtained under the condition of 980 °C/10 min/20 MPa, close to that obtained through Ni foil. The (Ni,Ti,Nb,Fe,Cr) multi-component phase formed at TiNiNb/GH536 interface became the new weak link of the joint.