Structure and Mechanical Properties of Impregnated Diamond Cutting Tools Using Cu-Based Metal Matrix

Abstract

Cu-based metal matrix, Ti coated and uncoated diamond composite were prepared by hot-press sintering in vacuum. The effects of the mixing time and the sintering temperature on the relative density, hardness and transverse rupture strength (TRS) of the matrix were studied. Structures of specimens sintered at different temperatures were studied by XRD. The TRS and wear resistant of coated and uncoated diamond segment were compared. The results show that the optimum mixing time is 20 hours; with the increase of sintering temperature, the relative density, hardness and TRS of the matrix firstly increase and then decrease; the TRS of diamond segment is lower than the matrix sintered at the same temperature and TRS of Ti coated diamond segment increased by 6.18% as compared with uncoated diamond segment; moreover the wear resistance of Ti coated diamond segment is better than that of uncoated diamond segment.

Effect of Ti Element on the Mechanical Properties of Cu-Matrix Bonding Diamond Tool Bits

“…However, owing to its relatively low hardness, low strength, high toughness, and low intensity combined with diamond (chemical affinity and mechanical control force are both weak), therefore these shortcomings limit their application. In order to improve the bonding strength between Cu-matrix bonding and diamond grits, adding other metal elements into Cu-matrix bonding is a effective method, because them can reduce the interfacial tension within Cu-matrix bonding and diamond, improve wettability between Cu-matrix bonding and diamond, and increase the comprehensive performance of Cu-matrix bonding diamond tools [6,7]. Among the commonly used active metals, Ti added in Cu-based alloys can form a transient TiC layer between the bonding matrix and the diamond grits at a temperature as low as 900 • C. Besides this interfacial layer, various inter-metallic compounds precipitated in the bonding matrix can further alleviates the interfacial stress associated with mismatch in thermal expansion coefficient and phase transformation during cooling [6].…”