A study on friction and wear reduction due to porosity in powder metallurgic gear materials

It has been widely acknowledged that controlled texturing on a surface can contribute to friction and wear reduction at lubricated sliding contact interfaces. This paper investigates the influence on friction and wear of different pore size distributions of powder metallurgy gear materials. The pore sizes are controlled by different densities of the powder metallurgic materials. Two different kinds of powder metallurgy (PM) gear materials were applied and a standard gear material are used as a reference. The friction and wear coefficients of PM materials sliding on PM materials increase with increasing pore size. The friction and wear coefficients of regular steel sliding on PM materials decrease with increasing pore size. No matter what the material of the disc, peeling is one of the main damage mechanisms of powder metallurgy pins with the biggest porosity.