The {332}<113> Twinning Behavior of a Ti-15Mo Medical Alloy during Cyclic Deformation and Its Effect on Microstructure and Performance

Materials (Basel). 2024 Mar 22;17(7):1462. doi: 10.3390/ma17071462.

Abstract

In this study, the microstructural evolution of a Ti-15Mo medical alloy was investigated, when the in situ cyclic tensile strain had 2% amplitude and the tension-compression cyclic deformation had 1%, 2%, and 3% amplitude. The Vickers hardness and wear resistance of the alloy were also optimized due to the grain-refining effect after cyclic deformation and annealing. The twinning-induced plasticity (TWIP) was considered the main deformation mechanism of the Ti-15Mo alloy during the tensile-compressive cycle deformation with suitable strain amplitude. The {332}<113> twins and boundaries were the main contributors to the grain refinement. The optimal microstructure, hardness, and wear resistance were obtained in the alloy deformed by tension-compression cyclic strain with a 3% strain amplitude. The wear resistance of the annealed alloy in Hank's solution was excellent in contrast to the original Ti-15Mo alloy due to its reasonable microstructure and hardness. It is clear that abundant twins were formed and retained in the coarse grains of the original alloy after cyclic deformation and annealing, which provided the expected refined grains and performance.

Keywords: cyclic deformation; medical titanium alloy; twinning-induced plasticity; wear resistance; {332}<113> twin.