Structure and high temperature frictional behavior of a coal pitch-derived carbonaceous mesophase (CM) treated by high-energy ball milling

A coal tar pitch-derived carbonaceous mesophase (CM) was treated in a high-energy ball mill apparatus. The structures for the raw and the as-milled CMs were characterized by X-ray diffraction and laser-Raman spectroscopic techniques, and the frictional behaviors for the CMs were investigated by using a SRV high temperature friction and wear tester. The results have shown that, high-energy ball milling leads to a drop in the crystallinity of the CMs and a decrease in the size of graphite planar micro-crystals, implying a higher structural amorphism caused by the high-energy ball milling. In addition, the CMs display a high temperature lubrication effect. High-energy ball milling is supposed to be beneficial to the graphitization of the CMs induced by friction mechanical action, and, therefore, facilitate the high temperature lubrication effect to some extent.