Microstructure and mechanical properties of vacuum brazed diamond abrasive segments with zirconium carbide reinforced Cu-based active filler metals

Abstract

Herein, by using Cu–Sn–Ti alloys addition zirconium carbide (ZrC) reinforcement to provide a way of enhancing the strength of brazed joint between diamond and solder. Microtopography of brazed segments was observed and interfacial characteristics of the brazing diamond were analyzed in detail via Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The wear machining performance of the diamond segment at different braze process was measured by changing the brazing temperature and holding time, respectively. Experiments indicated the microtopography of brazed segments with composite alloy of 15 wt% ZrC addition was optimal which the diamond edge was obvious, and the brazing filler metal spread more continuously and uniformly around the diamond without cracks and holes. Interfacial characterization results indicated that 10% wt% ZrC addition can promote titanium carbides produced on the diamond surface owing to the capillary force can improve the wettability. 15% wt% ZrC addition can further promote titanium carbides produced and improve the wettability by increasing the capillary force. However, higher ZrC addition (x ≥ 20 wt%) reduced performance of welded joints. Different braze process results showed that the brazed joint with the best grinding performance was obtained when the brazing temperature was 980 °C and the holding time was 15 min.