Dependence of mechanical properties of diamond segments on their composition

Abstract

The work is devoted to studying the mechanical characteristics of diamond-drilling-tool matrix. The infiltration method at temperature of 1100–1150 °C for 15 min in hydrogen medium was used for production of model diamond-containing and diamond-free samples of 24×7×8 mm matrices of two types, which differ in the contents of nickel and cast tungsten carbide, namely WС–Co–Cu (1) and WС–Со–Cu–Ni + cast tungsten carbide (2). Dia- monds A8K160 (500/400 μm), AC50 (500/400 μm) and SDB1125 (30/40 mesh, i. e. 600/425 μm) were used as filling materials - their density in matrix was 9 vol.%. Bending strength, hardness, density, porosity, and abrasive resistance of drilling tool matrix samples have been measured. It is found that WС–Со–Cu–Ni matrix samples have higher hardness and abrasive resistance as compared with WС–Со–Cu, these characteristics are explained by existence of nickel and cast tungsten carbide solids in them. Introduction of diamonds in the matrices results in sugnificant increase in their hardness (by 8–10 HRC units), distorting the hardness measured data of matrices in diamond layer of crown bits.