Effect of Pulse Width on TiNi Side Interface of Laser Welded Joint of TiNi/Stainless Steel

TiNi alloy/Ni/321 stainless steel laser welding joint with thickness of 0.2 mm was obtained using Ni as filler material in laser micro-welding. The effect of laser pulse width on the TiNi side interface of the welding joint was studied. The results show that the interface zone of TiNi alloy side under different pulse widths is composed of TiNi eutectic layer and TiNi3 intermetallic layer with different widths. With the increase of pulse width, the average width of TiNi eutectic layer gradually decreases, the average width of TiNi3 intermetallic compound layer increases gradually, and the microhardness of interface zone increases. The change of the melting amount of TiNi and the flow of Marangoni are the main reasons that affect the width and microhardness of the interface zone. © 2019, Science Press. All right reserved.