In this work, Ti–3Si-1.5Fe–1Mo titanium alloy reinforced with in-situ synthesized Ti₅Si₃ was prepared, and ultrahigh hardness (55.6 HRC) was achieved by solution aging treatment. The effects of Ti₅Si₃ on the friction and wear behavior of the alloy were investigated. Results show that the wear rate of the alloy after hot treatment increases from 3.51 × 10⁻⁴ mm³ N⁻¹ m⁻¹ to 3.93 × 10⁻⁴ mm³ N⁻¹ m⁻¹, yet the ultrahigh hardness alloy exhibits poor wear resistance. A series of the wear tracks characterizations and thermodynamical calculations were performed to elucidate its wear mechanism: during the reciprocating sliding, the reduction of the Ti₅Si₃ content leads to the increase of the friction pair force on the matrix, TiO₂ and SiO₂ wear debris are generated then fall off, both the oxidative wear and adhesive wear aggravated, which seriously impair the wear resistance of the alloy.

本工作制备了原位合成Ti ₅ Si ₃增强的Ti-3Si-1.5Fe-1Mo钛合金，并通过固溶时效处理获得了超高硬度（55.6 HRC）。研究了Ti ₅ Si ₃对合金摩擦磨损行为的影响。结果表明，热处理后合金的磨损率从3.51 × 10 ^-4  mm ³  N ^-1  m ^-1增加到3.93 × 10 ^-4  mm ³  N ^-1  m ^-1，但超高硬度合金的耐磨性较差。进行了一系列磨损轨迹表征和热力学计算以阐明其磨损机制：在往复滑动过程中，Ti ₅ Si ₃含量的减少导致基体上的摩擦副力增加，TiO ₂和 SiO ₂磨屑产生后脱落，氧化磨损和粘着磨损均加剧，严重损害合金的耐磨性。