Microstructural evolution and properties of TLP diffusion bonding super-Ni/NiCr laminated composite to Ti-6Al-4V alloy with Cu interlayer

Publication date: 5 December 2017
Source:Materials & Design, Volume 135
Author(s): Kun Liu, Yajiang Li, Chunzhi Xia, Juan Wang
Transient liquid phase (TLP) diffusion bonding super-Ni/NiCr laminated composite to Ti-6Al-4V alloy was performed at 950°C with the pressure of 5MPa. Two configurations (super-Ni/Cu/Ti-6Al-4V and Ni80Cr20/Cu/Ti-6Al-4V) were designed to explore interfacial microstructure evolution and mechanical properties. Results showed that the joint of laminated composite and Ti-6Al-4V alloy was mainly divided into two diffusion layers and a reaction layer. The interface was composed of Ni(Cu), Cu(Ni), Ti2Cu, TiCu, Ti3Cu4, Ti2Cu3 and Ti-Cu eutectic microstructure. The width of each layer increased with prolonging the bonding time and the growth rate of interfacial layers was dominated by the diffusion rate of alloying elements i.e. Cu, Ni and Ti. The maximum value of shear strength for both two configurations was about 58MPa.

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