Research on Friction and Wear Properties of Self-Lubricating Liner by Orthogonal Experiment

With the polytetrafluoroethylene （PTFE）/aramid (Nomex) fiber mixed woven self-lubricating liner as the research object, pressure （50, 100, 150 MPa）, reciprocating frequency （0.1, 0.3, 0.5 Hz） and temperature （20, 71, 163 ℃）were selected to design the orthogonal experiment scheme. The influence of pressure, reciprocating frequency, temperature and their interaction on the friction and wear properties of self-lubricating liner was studied by the matrix analysis method. The results show that under 50 MPa low pressure condition, the liner experienced mainly surface resin wear. Under 100 MPa medium pressure condition, in addition to the surface resin wear, there were also wear of PTFE fibers and Nomex fibers. Under 150 MPa high pressure condition, the surface resin of the liner was rapidly crushed and fragmented, and the PTFE and Nomex fibers underwent fracture. The friction coefficient first decreased and then increased with the increase of the pressure or temperature, increased with the increase of the reciprocating frequency. The volume wear rates increased with the increase of the pressure, decreased with the increase of the reciprocating frequency, and first increased and then decreased with the increase of the temperature. The factors affecting the friction coefficient and volume wear rate of the liner were ranked in descending order of influence as follows: pressure, reciprocating frequency and temperature. The minimum combined value of friction coefficient and volume wear rate was achieved at a pressure of 100 MPa, a reciprocating frequency of 0.5 Hz, and a temperature of 20 ℃.