Mechanical and Tribological Properties of Fe−Cu−Ni−Sn Materials with Different Amounts of CrB2 Used as Matrices for Diamond-Containing Composites

Abstract

The effect of the addition of CrB2 in the amount of 0 to 8 wt % on the microstructure, microhardness, elastic modulus, friction coefficient, and wear resistance of the Fe–Cu–Ni–Sn composites formed by cold pressing and subsequent sintering with hot pressing is investigated. It is found that an increase in the content of CrB2 in the composition of the composite material is accompanied by an increase in its hardness and elastic modulus. The coefficient of friction and the wear rating, as well as the H/E and H3/E2 parameters—which describe the resistances of a material to the elastic fracture deformation and to plastic deformation, respectively—decrease with an increase in the content of CrB2 to 2 wt % and increase with an increase in the content of the additive. A substantial increase in the wear resistance of the sample containing 2 wt % of CrB2 compared to the initial sample is caused by the formation of fine-grained microstructure and by the optimal combination of hardness and elastic modulus values. Tribological tests of sintered samples on pin-on-disc and Calo testers indicate substantial improvement of functional properties of the developed composite containing 2 wt % of CrB2.