Fabrication and characterization of Ti–Al intermetallics through accumulative roll bonding

Diverse manufacturing techniques are available for fabricating lightweight, strong aluminum (Al)–titanium (Ti) alloys for aerospace, automotive, and biomedical sectors, with accumulative roll bonding (ARB) as a promising severe plastic deformation method for alloy production. In this research article, Ti–Al intermetallic phases were synthesized through the ARB process, investigating the impact of thickness reduction up to 50% and the number of ARB passes on the formation and evolution of Ti–Al intermetallic phases. The microstructure of the phases and compounds that were formed was meticulously characterized through the utilization of a microscope, spectroscope, and diffractometer. The analyses confirmed the occurrence of alloying, transitioning from a micro-composite of Ti–Al layers. Heat treatment after three cycles of ARB followed by an annealing process at 550°C and 1050°C facilitated the formation of soft phases and enhanced homogeneity, forming Ti–Al intermetallic phases. The ARB process led to progressive homogenization of microhardness values, increasing from 129 HV after the second cycle to 133 HV after the third cycle, attributed to phase fragmentation and matrix straining. Subsequent heat treatment at 550°C enhanced microhardness to 229 HV and tensile strength to 94.64 MPa with a maximum strain of 0.06.