Tribological and compressive creep properties of polytetrafluoroethylene/nickel‐titanium shape memory alloy composites

Abstract

AbstractIn order to improving the reliability and service life of polytetrafluoroethylene (PTFE) composites. Micro nickel‐titanium shape memory alloy (NiTi) particles were incorporated with PTFE powder to develop the PTFE composites by using filling modification technology. Herein, 25 kinds of PTFE composites with different contents of micro NiTi particles were prepared, of which the tribological and compressive creep properties were investigated in detail considering the factors such as the NiTi content (0, 10, 20, 30, 40, and 50 wt%), cold‐pressed pressure(10, 20, 30, 40, and 50 MPa), and tested conditions(10 N, 10 Hz, 6 mm, 20 min). The filled different contents of NiTi particles could effectively enhance the compressive strength and creep resistance of PTFE composites, and the creep resistance would be notably improved by about 60% at elevated temperature. NiTi particles, as hard particles, did not increase the coefficient of friction (COF) of PTFE composites, and the lowest COF is 0.139. When the NiTi content is 50 wt%, the reduction of wear rate is 74% compared to pure PTFE. Indicating that NiTi particle fillers would significantly reduce the wear rate of PTFE materials and improve its anti‐wear performance. The research shows that NiTi could effectively improve the mechanical properties and tribological properties of PTFE composites, which provides a new idea for the selection of equipment sealing materials.