| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1640913 | Materials Letters | 2016 | 4 Pages |
•A hybrid joint based on two kinds of bonding mechanism.•The unmelted part of Nb interlayer acted as a diffusion barrier between Ti and Fe.•The unmelted Nb interlayer was beneficial to relieve and accommodate the thermal stress.
Pulsed laser welding of TC4 Titanium alloy to SUS301L stainless steel with Nb sheet as interlayer was applied and a hybrid joint was obtained comprising two metallurgical bonding zones based on two different kinds of joining mechanisms. During welding, the laser was focused near the Titanium alloy-Nb interface, so that Titanium alloy and Nb sheet partially melted and fusion welding process was realized at the Titanium alloy-Nb interface, while liquid phase diffusion bonding occurred at the Nb-stainless steel interface due to eutectic reaction between Fe and Nb element. No Ti-Fe intermetallic was detected in the weld showing that interdiffusion and reaction between Ti and Fe was effectively prevented. A reaction layer was formed at the Nb-stainless steel interface with the main microstructure of Fe7Nb6, Fe2Nb and α-Fe. The joint fractured at the reaction layer with the maximum tensile strength of 370 MPa.
