Titanium alloy bar with high fatigue performance and preparation method thereof

Abstract

The invention discloses a high-fatigue-performance titanium alloy bar and a preparation method thereof, and relates to the technical field of titanium alloy surface treatment.The preparation method comprises the following steps that a titanium alloy bar is taken as a base body, and a TiAl alloy coating is deposited on the surface of the titanium alloy bar; and then low-temperature ion nitriding is conducted, a nitriding layer is formed, and the high-fatigue-performance titanium alloy bar is obtained. Through surface TiAl alloying and low-temperature ion nitriding, a composite surface modification layer is formed on the surface of a titanium alloy matrix, Cu, Ni and Al contribute to refinement of nitride grains, sufficient Ti elements are provided for subsequent nitriding, a nitriding layer which is firmly combined with the matrix, high in hardness and high in abrasion resistance is formed, meanwhile, residual compressive stress is introduced to the surface, and therefore the corrosion resistance of the titanium alloy matrix is improved. Therefore, the anti-fatigue performance of the titanium alloy bar is remarkably improved, and the microstructure and performance characteristics of a titanium alloy matrix are kept.