Microstructure and Mechanical Properties of Ti/Al/Ti Laminated Composites Prepared by Hot Rolling

Abstract

Ti-6Al-4V/Al 3003/Ti-6Al-4V laminated composites were fabricated by hot roll bonding. The microstructure and mechanical properties of the Ti/Al/Ti laminated composites were investigated. The Ti/Al/Ti laminated composites exhibited a good Ti/Al interfacial bonding with straight interface. The development of microstructure through the thickness of Al layer was inhomogeneous. The initial grains in the region near the interface of Al/Ti were markedly fragmented into equiaxed fine grains, whereas the grains in the center of Al layer were markedly elongated along the rolling direction. The inhomogeneity of deformation through the thickness of Al layer can be attributed to the effect of the uncoordinated deformation between Al and Ti layers and the inhomogeneity of initial microstructure. For the Ti/Al/Ti laminated composites fabricated with approximately 37% reduction, the UTS and YS increased with increasing rolling temperature, while the EL increased slightly. For the Ti/Al/Ti laminated composites fabricated at 400 °C, the UTS and YS increased significantly with increasing rolling reduction, whereas the EL decreased. The bonding strength increased with increasing rolling temperature and reduction.