Regular Article

Laser welding-brazing of alumina to 304 stainless steel with an Ag-based filler material

¹ School of Mechanical Engineering, Xinjiang University, Wulumuqi 830000, PR China
² Key Laboratory of Automobile Materials, School of Materials Science and Engineering, Jilin University, Changchun 130022, PR China
³ State Key Laboratory for Manufacturing Systems Engineering, Xian 710000, PR China

^* e-mail: yanzhang4967@163.com

Received: 28 September 2020
Accepted: 10 November 2020

Abstract

In this paper, laser welding-brazing of 304 stainless steel (SS) and Al₂O₃ ceramic dissimilar metal material was carried out. The results showed that the SS and Al₂O₃ were joined by melting filler metal when the laser was focused on the SS side of the joint. One process was one pass welding involving creation of a joint with one fusion weld and one brazed weld separated by remaining unmelted SS. When laser beam was focused on the SS plate 1.5 mm, SS would not be completely melted in joint. Through heat conduction, the filler metal (68.8 wt.% Ag, 26.7 wt.% Cu, 4.5 wt.% Ti) melting occurred at the SS-Al₂O₃ ceramic interface. A brazed weld was formed at the SS-Al₂O₃ ceramic interface with the main microstructure of Cu[s.s.] + Ag[s.s.], Ti₂Cu + TiFe and Ag + AlCu₂Ti. The joint fractured in reaction layer at the ceramic side with the maximum tensile strength of 74 MPa.