The effect of Ti and TiH<sub>2</sub> additives on structure and mechanical properties of copper alloys for diamond cutting tools

Abstract

The study covers the effect of titanium and titanium hydride additives on the structure, mechanical properties, and wear resistance of copper alloys to be used as a binder for diamond cutting tools. Cu-Ti and Cu–TiH 2 powder mixtures were obtained by mechanical alloying in a planetary ball mill. This treatment made it possible to obtain single-phase copper-based solid solution powders in the Cu-Ti system and two-phase copper-based powders with uniformly distributed submicron TiH 2 particles in the Cu-TiH 2 system. It was found that Cu-2.5%Ti and Cu-10%TiH 2 compact samples feature by maximum mechanical properties (2.0-3.5 times higher than that of pure copper). Hardening in these alloys is implemented by the solid-solution mechanism and due to the Cu 3 Ti 3 O phase formation. Grains of this phase have a higher dispersion in alloys with TiH 2 used as a titanium-containing additive. This provides a high value ofbending strength (920 MPa) and hardness (114 HB). According to the results of comparative tribological tests, it was found that Cu—10%TiH 2 samples have the best wear resistance. After pin-on-disk tests, the equivalent wear of these samples was an order of magnitude less than that of pure copper and 5 times lower than that of Cu—2.5%Ti samples.