Kinetics of joint formation during diffusion induced solid state bonding of titanium and magnesium alloys

Abstract

This study explores the diffusion bonding of titanium to magnesium. The microstructural evolution and intermetallic compounds formed within the bond region are studied. The microstructure and composition of the bonds were characterized using a Scanning Electron Microscope (SEM) equipped with Energy Dispersive Spectroscopy (EDS). The mechanical properties of the bonds were evaluated using a micro-hardness test to determine the hardness variation across the joint region, while shear strength measurements were used to evaluate the joint strength. The results indicated that solid state diffusion bonding of Ti6Al-4V and Mg (Az31) lead to the formation of Ti3Al and Ti2Mg3Al18 reaction layers within the joint region. Evaluation of the mechanical properties of the bonds revealed that the bond strength increased with increase bonding time to 116 MPa at a bond time of 1 hr. The joint formation and strength was attributed to dispersion strengthening due to the nucleation of dispersed intermetallic compounds at the joint interface.