Interface strengthening and microstructural evolution of 316H/TC4 composite plate driven by heterogeneous plastic deformation

In this study, the common challenges of 316H/TC4 composite plate, such as weak interface bonding, poor coordinated deformation and serious warpage, were caused by the mismatch of thermodynamic properties of dissimilar metals during the traditional rolling process. The preparation of high-quality 316H/TC4 composite plates was achieved by adopting the vacuum corrugated rolling process and introducing non-uniform shear strain. The results show that, compared with the traditional flat rolling or asynchronous rolling, the process induces periodic strong shear deformation in the interface region, promotes the dynamic recrystallization of TC4 side and the grain refinement of 316H side, and the element diffusion distance is significantly enhanced. The interfacial shear strength is increased to 339.26 MPa, and the fracture mode is changed from brittle peeling of the interface to ductile tearing. Combined with the thermal-mechanical coupling finite element simulation, the strengthening mechanism of non-uniform plastic deformation on the interface bonding was revealed, providing an effective approach for the preparation of high-performance titanium/steel composite plates.