TRIBOLOGICAL BEHAVIOR OF THERMOPLASTICS A T LOW-TEMPERATURES

The lubrication of sliding bearings for application to low temperature s is difficult, caused by the special failure after long standing of t he most lubricants. An alternative is given by so-called ''self-lubric ated'' thermoplastic materials. Thermoplastic based composites with di fferent filler materials have a good mechanical and thermal load capac ity up to temperatures T = 200 degrees C. The addition of sliding modi fiers gives low friction coefficient and wear. Unknown is the behaviou r of these materials at low temperatures. The aim of this work is to d evelope a rest facility to estimation the tribological behaviour of ma terials at temperatures up to T = - 196 degrees C and to investigate t he application of different thermoplastic materials in friction with a steel of typ 100Cr6 as the counterbody under dry wear condition. Adva nced thermoplastics, e.g. PPS, PAEK, PES or PI and PTFE with different fillers using for the investigations at temperatures T = - 40 degrees C, room temperature and T = 160 degrees C. The typical failure mechan ism depending on the proof temperature are discussed.