Microstructures and Mechanical Properties of Mg-9Al/Ti Metallurgical Bonding Prepared by Liquid-Solid Diffusion Couples

Abstract

Microstructures and mechanical properties of Mg-9Al/Ti metallurgical bonding prepared by liquid-solid diffusion couples were investigated. The results indicate that a metallurgical bonding was formed at the interface Mg-9Al/Ti, and the Mg17Al12 phase growth coarsening at the interfaces with the increase in heat treatment time. Push-out testing was used to investigate the shear strength of the Mg-9Al/Ti metallurgical bonding. It is shown that the shear strength presents an increasing tendency with the increased heat treatment time. The sequence is characterized, and the results show that the fracture takes place along the Mg-9Al matrix at the interface. The diffusion of Al and Ti elements play a dominant role in the interface reaction of Mg-9Al/Ti metallurgical bonding. By energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD) and thermodynamic analysis, it was found that Al3Ti is the only intermetallic compound at the interface of Mg-9Al/Ti metallurgical bonding. These results clearly show that chemical interaction at the interface formation of Al3Ti improves the mechanical properties of Mg-9Al/Ti metallurgical bonding.