Influence of Graphite Content and Shape on the Cu-Based Sintered Friction Materials

동계 소결마찰재에 대한 흑연함량과 형상의 영향

Influence of frictional and mechanical properties was studied with the content(8-18 wt.%) and shapes(flake of irregular) of graphite that was used as lubricant components of copper-based sintered materials. The density, hardness and bending strength of friction materials with the shape of flake graphite were lower and decreased rapidly than that of irregular, as the content of graphite increases up to 18 wt.%. In friction test, wear rate was about 2.0-$2.5{\times}10^{-7}\textrm{cm}^3$/kgf.m and coefficient of friction was 0.30-0.37, independent on graphite content and shape. As the temperature of friction materials increased, wear rate decreased rapidly because oxides such as $Cu_2O$ and $SnO_2$ in the surface of friction material were formed.