Study on the Friction and Wear Mechanism of Irradiated PTFE

The internal linear long chain and parallel lamellar structure of traditional PTFE lead to weak intermolecular forces, easy delamination during friction, and poor wear resistance. In this work, the main chain of PTFE was moderately broken by irradiated‐modified technology, and self‐grafting and local cross‐linking occurred to form a branched structure, and the compressive elastic modulus of irradiated PTFE was increased to 720 from 580 MPa of unirradiated PTFE. The low molecular chain segment promotes the transformation of the crystal to the radial spherulite and effectively inhibits the delamination. Compared with unirradiated PTFE, the wear rate of irradiated PTFE decreased by three orders of magnitude, and the wear debris was transformed into micro/nano particles, which made it difficult to form a complete transfer film on the friction pair surface, and the friction coefficient increased by 0.16. Based on the unique molecular structure of irradiated PTFE, the constructed rigid abrasive wear model can clarify the wear mechanism of micro/nano debris produced by the asperity of the friction pair and provide a theoretical basis for the application of PTFE friction pair with branched molecular chain and spherulite structure.