Recrystallization Behavior at Diffusion Bonding Interface of High Nb Containing TiAl Alloy

Abstract

A series of diffusion bonding tests are conducted on a high Nb containing TiAl alloy with full lamellar (FL) microstructure and the effect of interfacial recrystallization behavior on the shear strength is discussed. Microstructural observations reveal that bonding above 1 100 C and 30 MPa results in recrystallization at the bonding interface flanked by FL microstructure, thus promoting the interface migration and leading to a sound joint. Based on the present results, the nucleation mechanism of recrystallization at the bonding interface is studied. Shear testing results show that recrystallization at the bonded zone improves the bonding quality of the joints by changing the failure mode. The shear strength of the joints attains 400 MPa when bonding at 1 150 C/30 MPa/45 min and 1 100 C/40 MPa/45 min.

The Influence of Surface Roughness on Diffusion Bonding of High Nb Containing TiAl Alloy

“…We can find that the highest shear strength is 383MPa for the bonded joint which was produced with the parameters 1150℃ /30MPa/45min/0.062μm.This shear strength attains about 98% of the matrix materials. That similar shear strength value were also reported by Cam et al [15] for diffusion the gamma-TiAl alloys and Bin Tang et al [18] for the high Nb containing TiAl alloys. The fact that the shear strength of the bonding joints increase which was caused by the disappeared of the α 2 (Ti3Al) phase and the sufficient recrystallization at the diffusion bonding interface.…”

One-Step Fabrication of 3D Nanohierarchical Nickel Nanomace Array To Sinter with Silver NPs and the Interfacial Analysis

“…Larger pressure and higher temperature were usually needed in the traditional solid-state diffusion bonding process. For example, the TiAl alloy solid-state diffusion bonding needs 1100 °C and 30 MPa . The extra heating energy and pressure, which would assist in bonding between different metals, were employed to accelerate the surface oxide removal, leading to plastic deformation and ultimately achieving solid-state diffusion bonding.…”

Research advances on homogenization manufacturing of heavy components by metal additive forging

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