Interfacial characteristics and bending properties of a Ti6Al4V-Mg3AlZn laminate metal composite

In this paper, a Ti6Al4V-Mg3AlZn laminate metal composite (TC4-AZ31 LMC) was successfully prepared by hot pressing sintering. The interfacial microstructure of this composite was investigated using scanning electron microscopy (SEM), electron back-scattered diffraction (EBSD) and high resolution transmission electron microscopy (HR-TEM). The three-point bending (TPB) tests of TC4-AZ31 LMC were performed to determine the foil-foil interface bonding properties. Results show that the AZ31 matrix of the TC4-AZ31 LMC possesses a strong {10-10} sheet texture and the adjacent AZ31 foils are bonded well through the migration of grain boundaries across the original boundaries of the foils. A continuous interfacial reaction layer consisting of an intermetallics layer, a nanocrystalline-amorphous mixture layer and a bulk-precipitated particles region was formed around the TC4/AZ31 interface. The intermetallics layer bordering on TC4 reinforcement was identified as Al192.40Fe46.22 phase. The nanocrystalline-amorphous mixture layer was composed of MgO nanocrystalline and Mg-O amorphous phase. The bulk-precipitated particles locating at the boundary of AZ31 matrix were determined as complex precipitates containing Al6Mn and Al13Fe4 phases. Compared with the AZ31 alloy, the TC4-AZ31 LMC possessed a superior bending strength, which is attributed to the effective load transfer capability from the AZ31 matrix to high strength TC4 reinforcement through the well-bonded TC4/AZ31 interface. •The interfaces of TC4-AZ31 LMC were studied by EBSD and TEM systematically.•The extremely thin intermetallics and nanocrystalline-amorphous reaction layers were formed along the TC4/AZ31 interface.•The grains of AZ31/AZ31 interface were bonded together by grain boundaries migration.•The composite showed superior bending properties than AZ31 alloy.