Microstructure and performance of glass fiber metal composite-bonded diamond segment with Cu-Sn-Ti alloy

To develop metal-bonded diamond tools without dressing during machining, a novel glass fiber metal composite bonding agent with Cu–Sn–Ti alloy was proposed. The three-point bending strength of the diamond segments and the Vickers microhardness of the solidified composite bonding agents were tested. The microstructures of the diamond segments were investigated and the wear tests were performed for each group of diamond segments. The results showed that diamond segments with glass fiber content of 1.55 wt % - 6.89 wt % exhibited lower bending strength (declined by 36.4%–80.4%) and smaller microhardness (reduced by 16.0%–87.9%), compared to those of the diamond segment with no glass fiber addition. Good bonds were formed among the Cu–Sn–Ti alloy, glass fibers, and diamond grits. Chemical reactions occurred between the Cu–Sn–Ti alloy and glass fibers during high-temperature brazing, forming new intermetallic compounds such as Ti₅Si₃, Ti₂O₃, and Ti(Cu, Al)₂, which improved the bonding strength. With an increase in the glass fiber content, fractures were more likely to occur in the glass fibers than in the diamonds, resulting in the bending strength decreasing more and more slowly. The wear resistance of the diamond segments decreased gradually with increasing glass fibers weight content. The diamond segment with 4.98 wt % glass fibers exhibited the best and most stable wear performance.