Effects of test temperature on the ball-on-slab wear behavior of nickel-titanium shape memory alloys fabricated by laser powder bed fusion
Xianghui Huang, Nan Kang, Pierre Coddet, Mohamed El Mansori
Abstract
This work investigated the effects of test temperature on the ball-on-slab wear behavior of nickel-titanium (NiTi) alloy fabricated by laser powder bed fusion. The average steady-state coefficients of friction (COFs) at 16 °C, 36 °C, and 56 °C are similar, with an average of 0.61 (standard deviation 0.03), rising to 0.75 at 76 °C. The larger COFs at 76 °C can be ascribed to the large strain fluctuations around the estimated contact stress and more bulging debris. However, after 60 min of wear, the specific wear rate at 76 °C is the smallest (1.36 ± 0.4 × 10-4 mg/N·m) due to the largest elastic deformation energy of austenite and more adhesive debris. In addition, the dominant wear mechanisms of adhesive, abrasive, oxidative and delamination were discussed in depth.