Ti3SiC2 -: A layered ceramic exhibiting ultra-low friction

Currently known solid lubricants will sometimes exhibit ultra-low coefficients of friction, (mu < 5 x 10(-3)) under carefully controlled conditions, but mu is rarely lower than 0.05 ina realistic service environment. The layered carbide-derived ceramic, Ti3SiC2, has been shown recently to have many exceptional electrical and mechanical properties. We report lateral force microscopy measurements which show mu < (2-5) x 10(-3). The ceramic has planes of easy cleavage as demonstrated by FeSEM and AFM images and previous studies of its mechanical behaviour. It is on such cleavage faces that the lowest values of mu were recorded (sometimes below the limit of resolution). The ultra-low friction persists after exposure to ambient air for several months. (C) 1999 Elsevier Science B.V. All rights reserved.