Tribological behavior of high specific strength PTFE-Al alloy composite
(1. College of Materials Science and Technology,
Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
2. School of Materials Science and Engineering, Central South University,
Changsha 410083, China)
Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
2. School of Materials Science and Engineering, Central South University,
Changsha 410083, China)
Abstract: Solid lubricants lead to substantial weight savings relative to the use of liquid lubricant, especially in the weight-conscious aerospace industry. A new PTFE-Al alloy composite(A) containing 60% area proportion of PTFE composite was developed. Another type of common metal-plastics multilayer composite, also called DU, was selected for a comparative investigation. Friction and wear tests were carried out in an oscillating sliding tribotester in air at an oscillating frequency of 0.13Hz and contact mean pressures from 10 to 80MPa. The composites slid against a 38CrMoAlA steel shaft. The results show that the composite A exhibits low coefficient of dry sliding friction less than 0.1 and long wear life of 2000m. This is because the composite A can provide a sufficient solid lubrication during the whole tests. SEM examination of the transfer films for the composite A confirms that uniform, thin and coherent transfer films are prerequisites for low friction and good wear resistance.
Key words: composite; friction, wear; solid lubricant; polytetrafluoroethylene(PTFE); Al alloy; high load