Diffusion Bonding of Magnesium Alloy (AZ31B) to Cu by Using Sn Foil

Abstract. The experimental investigation of diffusion bonding of magnesium alloy (AZ31B) to Cu in vacuum was carried out by using Sn foil as transition metal. The microstructure of the welded joints was studied by SEM, EDS, XRD and the mechanical properties of the samples were tested by tensile experiments. The results show that: the microstructure at interface zone of diffusion brazing joint includes γ-Cu, Mg2Sn, Mg-Sn-Cu ternary intermetallic compounds, Mg17(Cu, Al)12 and (α-Mg+Mg2Sn) eutectic structure, and the width of diffusion zone increased with the extension of the holding time, the maximum can reach up to 400 μm under the condition of 420 ℃,90 min. The hardness of diffusion welding area was significantly higher than the substrate