Microstructure and strength of TiAl/40Cr joint
diffusion bonded with vanadium-copper filler metal
diffusion bonded with vanadium-copper filler metal
(State Key Laboratory of Advanced Welding Production Technology,
Harbin Institute of Technology, Harbin 150001, China)
Harbin Institute of Technology, Harbin 150001, China)
Abstract: Intermetallics TiAl was diffusion-bonded to steel 40Cr in vacuum furnace with interlayer V/Cu. The results show that infinite sosoloid that made for bond performance is formed at the interface of V/Cu and Cu/40Cr, and three acting layers are formed at the interface of TiAl/V including Ti3Al layer at TiAl side, intermittent V5Al8 layer in the middle and Ti-V sosoloid at V side. Fragile reactors V5Al8 arising at the interface lead to bad performance of joints, and the strength of the joint is 200MPa, while it was still higher than the strength of the joint intermetallics TiAl to 40Cr steel diffusion-bonded directly. Intermetallic TiAl and 40Cr steel are diffusion-bonded successfully by using a composite isolation layer V/Cu.
Key words: diffusion bonding; microstructure; TiAl; intermetallics; filler metal