Surface Friction and Wear Properties of the Semi-metallic Friction Materials with Nano-CaCO_3

The tribological properties of semi-metallic friction materials with nano-SiC were studied. The results indicate that when nano-CaCO_3 powders substituted for the general CaCO_3 powders in a semi-metallic friction material, the friction coefficient of this material decreased and the wear increased. From the SEM images together with the experimental data analysis, it was shown that when the dry powders containing nano-CaCO_3 powders were mixed, the nano-CaCO_3 particles adhered to the surfaces of other ingredients, and the bonding strength between resin and ingredients was reduced during hot molding of the mixture. It induced that the steel fibers and grains were easy to be disengaged from the friction surface under shear stresses.