Effect of Ti fracture on mechanical properties of accumulative-roll-bonded Ti–Al composite plates

In this study, the effect of the degree of hard-phase fracture on the mechanical properties of accumulative-roll-bonded metal composite plates using experimental tests and finite element simulations. Ti-Al plates with two compositions, i.e., those with fractured and continuous intermediate Ti layers, were used as base materials and subjected to accumulative roll bonding five times. The results showed that the fracture of the intermediate Ti layer significantly degraded the mechanical properties. However, the more the Ti layer was broken down and distributed within the composite plate during accumulative roll bonding, the better were the mechanical properties. Tensile fracture of the composite plate only occurred in the Al phase, with the crack path deflected around the Ti phase. The more compact the Ti distribution, the more severe the tearing and delamination of the Al phase. Through finite element simulations, it was concluded that the shorter the distance between the Ti fragments along the loading direction, the higher the stress and the strain rate, which resulted in premature fracture and degradation of the mechanical properties.