Influence of the layer thickness ratio of Ti/Al cladding strips on the interfacial stress state and tensile failure mechanism

Ti/Al cladding strips have been widely used in many fields owing to their light weight, high strength, and corrosion resistance. Clarifying the interaction mechanism between the constituent metals and the bonding interface during deformation is the key to evaluating the comprehensive properties of laminated composites. This study investigates TA2/AA6061 by simulating uniaxial tension with different layer thickness ratios via ABAQUS using the Johnson-Cook constitutive model. The distributions of stress, strain, displacement, Lode parameter, and stress triaxiality were analyzed to reveal stress evolution during tension. Micro-CT was used to characterize interfacial damage evolution. An approximate instability-point formula was derived from simulations and experiments to predict maximum elongation and tensile strength. Results indicate that the deformation behavior of Ti/Al cladding strips varies with the layer thickness ratio. Typically, the Ti layer possesses higher strength and better plasticity compared with the Al layer. However, constrained by the bonding interface, the cladding strips exhibit a triaxial stress state. To achieve coordinated deformation, the metallic constituents experience extra horizontal stress constraints, resulting in the Ti layer fracturing earlier than the Al layer during tension. Based on the tensile damage mechanism, the plastic instability prediction model was established, which provides a theoretical basis for predicting the mechanical properties of cladding strips with different layer thickness ratios. This study can provide a reference for the design of high-quality Ti/Al cladding strips for industry.