MECHANICAL-PROPERTIES AND STATIC FRICTION BEHAVIOR OF EPOXY MIXES AT ROOM-TEMPERATURE AND AT 77-K

Experiments were conducted to determine static friction coefficients for various epoxy mixes slid against copper at room temperature and at 77 K. Several of the mixes' mechanical properties were also measured as an aid to interpreting the friction results. At room temperature, mixes which exhibit a strong tendency towards viscoelastic behaviour also demonstrate a considerable time dependence in their static friction coefficients. At 77 K all of the epoxy mixes are in the glassy state, and their static friction coefficients are noticeably reduced from their room temperature values. Several Teflon® -powder-filled mixes were also tested to examine the consequences of incorporating a friction modifier into the epoxy. The mechanical properties of the Teflon-filled mixes are similar to those of the unfilled epoxies, with the exception that the particle-filled mixes are generally much more brittle. The use of the Teflon filler has the additional effect of reducing the friction coefficients for the epoxy mixes to values comparable to that of bulk Teflon. © 1990.