Investigation on the Microstructural Evolution and Mechanical Properties of Ti/Al/Ti Clad Sheets via Cryorolling and Annealing

Abstract

The Ti/Al/Ti clad sheets were fabricated through hot rolling (HR) and cryorolling (CR), followed by annealing treatment. The influences of cryogenic deformation and different annealing temperatures on the microstructure and mechanical properties of clad sheets were systematically investigated. Results showed that the CR clad sheet exhibited the highest tensile strength of 507 MPa. CR can fabricate the clad sheet with good interfacial bonding quality, devoid of defects such as pores and cracks. Moreover, CR introduced significant fine-grain strengthening and dislocation strengthening effects. After annealing, the Ti and Al layers underwent varying degrees of recovery and recrystallization, thereby improving the elongation of clad sheets, and attained optimal elongation at 773 K (28.3%). During annealing, the element diffusion layer thickness at the interface gradually increased with temperature, along with the enhancement of the metallurgical bonding effect, resulting in improved interfacial bonding strength. However, the mechanical properties of the clad sheet decreased at 823 K because of the production of TiAl₃ intermetallic compounds. The rolling and heat treatment processes utilized in this study provide valuable insights into the production of high-performance Ti/Al/Ti clad sheets.