Effect of binder with nano Ni on mechanicalproperties of TiC based hard alloys

Abstract

Titanium carbide based hard alloys with nickel-chromium binder possess high hardness, wear and heat resistance. In order to improve physical and mechanical properties of alloys the polycarbide basis TiC-5WC-5NbC and Ni (nano Ni)-Cr binder were used. The physical and mechanical properties of the alloys with 10, 18 and 24% (wt) of the binder, which contained 7,5, 13,5 and 18% (wt) of nano Ni or fine grained Ni respectively, were studied. It is found that the use of nano nickel (70 nm) compared to fine nickel (1..2 μm) allows to obtain lower porosity, more fine-grained microstructure (d = 0,7..1 μm) and higher physical and mechanical properties of the alloys by 10..15%. Binder with nano Ni prevents formation of carbide skeleton and the nano Ni content increase results in the hardness, micro hardness, transverse rupture strength and fracture toughness increase.

Effect of Production Methods on the Microstructure, Phase Composition, and Properties of Hard Alloy VK8 with Submicron Grain

“…However, another problem of nanostructure formation in carbide materials is the process of particle consolidation during sintering. The sintering in the presence of a liquid phase leads to fast grain growth caused by intensive mass transfer [8]. The diffusion processes can be retarded in solid-phase sintering; however, this makes impossible to get rid of residual porosity.…”