1 per cent) higher than the strength and modulus. Specific strength and modulus refers to the material's strength and modulus/density ratio, higher strength, smaller parts weight; higher modulus, more rigid parts. On the structure of high speed or reduce weight of means of transport is important. 2) in fiber-reinforced composites fiber-matrix interface effectively prevents fatigue crack growth, plus the load borne by the reinforcing fibers. Most of the fatigue strength limit is the tensile strength of the metal 30%~50%, and composites can be reached 60%~80%. 3) thermoplastic plastics mixed with a small amount of chopped carbon fibre can greatly enhance its wear resistance, its increasing multiples of the original several times. PVC reinforced with carbon fiber for its own 3.8 times, PTFE for itself 3 times times 2.5 times of polypropylene for its own; polyamide 1.2 times itself; polyester twice times itself. Proper compound can be used as wear-resistant steel plate and plastic objects, such as bearing materials. PTFE (or POM) for surface layer, porous bronze and steel plate for the inside of the three-layer composite, can be made into good material for sliding bearing.