Core equipment and key technologies for near-isothermal rolling forming of titanium-based difficult-to-form alloys

With the growing demand for lightweight and high-strength materials in the aerospace industry, lightweight difficult-to-deform metals—such as titanium-based alloys, TiAl, and Ti₂AlNb intermetallic compounds—have garnered significant attention due to their low density, high specific strength, and excellent high-temperature resistance. However, these materials exhibit poor room-temperature plasticity and high deformation resistance, which make them prone to defects such as cracking, poor plate shape, and inferior surface quality during traditional rolling processes. These challenges severely limit their practical engineering applications. This study is built upon the technical framework of “pre-rolling microstructure control – core equipment development – rolling process innovation.” By employing an in-situ particle-reinforced as-cast microstructure refinement process combined with near-isothermal multi-directional forging technology, the microstructural characteristics and deformation capacity of the rolling billets were effectively optimized. A closed-loop control system for roll induction heating temperature was established, and a coordinated thermal management strategy integrating induction heating and internal water cooling was developed. At a set temperature of 550??, the maximum temperature deviation across the roll surface was controlled within 25??, thereby achieving precise regulation of the roll surface temperature. Furthermore, key components for near-isothermal rolling and specialized rolling equipment were developed, enabling the production of large-scale, high-quality warm-rolled plates of lightweight difficult-to-deform alloys. Compared with conventional cold roll rolling processes, the warm roll rolling approach significantly improved both plate shape quality and surface roughness. Based on a cross-scale precise design methodology for pre-rolling microstructures—considering alloy composition, melting, and forging—and within the defined forming process parameter window, a Ti₂AlNb strip with a thickness of 0.1?mm was successfully fabricated. On this basis, a honeycomb structure prototype was further developed. The realization of package-free rolling for lightweight difficult-to-deform alloys lays a solid theoretical and technological foundation for the future high-quality manufacturing of complex structural components made from such materials.

Zhang Xinlong is a Ph.D. candidate at the School of Mechanical Engineering, Taiyuan University of Technology. His research is focused on the development of multi-energy field-assisted forming technologies for titanium-based difficult-to-deform alloys, under the supervision of Professor Han Jianchao