Friction and wear studies of polyimide composites filled with short carbon fibers and graphite and micro SiO2

Polyimide (PI) composites filled with short carbon fibers (SCFs), micro SiO2, and graphite (Gr) particles were prepared by means of hot press molding technique. The friction and wear properties of the resulting composites sliding against GCr15 steel were investigated on a model ring-on-block test rig. Experimental results revealed that single incorporation of graphite and SCF significantly improve the tribological properties of the PI composites, but micro SiO2 was harmful to the improvement of the friction and wear behavior of the PI composite. It is found that a combinative addition of Gr, SCF and micro SiO2 was the most effective in improving the friction-reducing and anti-wear abilities of the PI composites. Research results also show that the filled PI composites exhibited better tribological properties under higher PV-product.