Relationship between the structure and properties of sintered aluminum bronze base frictional materials

The optimum combination of frictional characteristics and wear resistance under unlubricated friction conditions is exhibited by materials containing 11–14 wt.% Al in their bronze matrix. The structure of the matrix of these materials consists of a heterogeneous mixture of a ductile (anα solid solution of aluminum in copper) and a brittle (the intermetallic compound Cu2Al) component, the concentration of the latter being sufficiently low to produce no marked decrease in strength. The presence in the structure of a second phase reduces the plastic deformation of the surface layer of the material during its sliding on the mating part, results in lower temperatures being generated on the frictional surfaces, prevents the components of the frictional pair from seizing with each other and, hence, increases the wear resistance of these frictional materials.