The role of prismatic slip dependent dynamic recrystallization in the fabrication of a submicrocrystalline Ti-Cu alloy with high thermostability
Hai Wang, Wei Song, Konrad Koenigsmann, Shuyuan Zhang, Ling Ren, Ke Yang
Abstract
When submicrocrystalline metal materials were first made available, their beneficial properties opened up various interesting design applications. However, several shortcomings soon became clear. One large problem is their complicated fabrication process, which cannot be applied on a large-scale industrial level. Another particularly vexing issue is their microstructural instability, which, even at lower temperatures, causes grains to rapidly coarsen. In this study, we have overcome these two problems in a submicrocrystalline Ti-Cu binary alloy. Contrary to conventional ideas of “microstructural heredity,” we have found that deformation with an initial coarse lamellar α′ microstructure when prism slip systems have been activated can remarkably refine grains to the submicron scale. We have also developed a strategy to improve the microstructural thermostability through Cu alloying, so that the submicrocrystalline grains formed during deformation at elevated temperatures can successfully be retained to room temperature. This study provides a theoretical foundation for the fabrication of submicrocrystalline titanium alloys using conventional hot rolling technology, which gives this alloy potential for further development within the titanium industry.