LIE Home • Issue Contents

Pulsed Laser Beam Welding (LBW) of Ti3Al-Nb Alloy to Stainless Steel Using a V/Cu Composite Interlayer
H.L. Guo, H.M. LI, C.J. Shen, D.Q. Sun, D. Wu and L. Wang

Weldability of Ti3Al-Nb alloy to 301L stainless steel is very poor due to the brittle Ti-Fe intermetallics and weld cracking. In this work V/Cu was used as composite interlayers to prevent the formation of these brittle phases when Ti3Al-Nb alloy was welded to 301L stainless steel with a Nd:YAG laser. The laser beam was focused on the Cu interlayer centreline for reducing fusion ratio of Ti3Al-Nb and weld Ti content. The presence of these composite interlayers and this process ensure that crack free welds were obtained. The V/Cu composite interlayers helped to reduce Ti-Fe intermetallics, promote the formation of Cu based and V-based solid solutions, and hence improve weld microstructure, cracking susceptibility and joint properties. The average tensile strength of the joint was 218 ± 13 MPa and the joint fracture occurred at Ti3Al/weld interface zone with the highest hardness of 707 HV. The Al-Cu-Ti, Cu-Ti intermetallics were the main factor of affecting the mechanical properties of Ti3Al-Nb alloy and stainless steel laser-welded joint.

Keywords: Nd:YAG laser, Ti3Al-Nb alloy, 301L stainless steel, laser beam welding (LBW), microstructure, mechanical properties

Full Text (IP)