Interfacial evolution and coordinated deformation mechanism of Ti/Al laminated metal composites prepared by diffusion bonding

Abstract

Laminated metal composites (LMCs) of titanium and aluminum (Ti/Al), combining the high strength and thermal stability of titanium with the low density and corrosion resistance of aluminum, hold substantial promise for industrial applications. Utilizing diffusion bonding under optimal processing conditions—specifically a bonding temperature of 550 °C and a holding time of 120 min—an average interfacial shear strength of 68.7 MPa was achieved. Transmission electron microscopy (TEM) revealed a metallurgically bonded interface facilitated by the mutual atomic diffusion of titanium and aluminum; this diffusion layer predominantly comprises the TiAl3 phase. Detailed insights into the microstructural evolution at the interface, including dislocation configurations, were also obtained in this study. The Burgers vectors of these dislocations were determined using the two-beam electron diffraction contrast imaging method. Based on these results, it can be elucidated that the deformation mechanism of Ti layer was dominated by the dislocation slip (mainly prismatic and the basal slip), while the coordinated deformation of TiAl3/Al interface benefitted by the dislocations gliding across the interface.