화학공학소재연구정보센터
Materials Chemistry and Physics, Vol.171, 73-82, 2016
Reaction-assisted diffusion bonding of TiAl alloy to steel
The dissimilar joining of TiAl to AISI 310 stainless steel by a reaction-assisted diffusion bonding process; using Ni/Al nanolayers as an interlayer, was investigated in the present work. The Ni and Al alternated nanolayers were deposited by d.c. magnetron sputtering onto the base materials, with a bilayer thickness of 14 nm. Joining experiments were performed at 800 degrees C for 60 min with compressive stress of 25 and 50 MPa. The effectiveness of the interlayer on the bonding process was assessed by microstructural characterization of the interface and by mechanical tests. Diffusion bonded joints were characterized by scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy (STEM) and analyzed by energy dispersive X-ray spectroscopy (EDS) in SEM and TEM and Fast Fourier Transform (FFT). The thickness of the interface region, together with its micro structural and mechanical characteristics, is affected by the use of Ni/Al multilayers; which promote joints with lower hardness values, closer to the values of the base materials, and exhibit higher shear strength. (C) 2015 Elsevier B.V. All rights reserved.