Effect of volume ratio between Cu-Sn-Ti alloy and vitrified binder on microstructures and mechanical properties of diamond segments

To improve the holding strength of bond to the diamond grits, a Cu-Sn-Ti alloy was introduced as an additive into the SiO₂-Al₂O₃-B₂O₃-Li₂O vitrified bond, which was then made into segments with diamonds. Some properties of the segments, namely microstructure, shrinkage, phase composition and mechanical properties, were characterized to determine the sintering temperature and the effect of volume ratio of Cu-Sn-Ti alloy in the vitrified bond on the segment performances was studied by SEM and XRD analysis. The results show that TiC phase is formed between the diamond and the cermet bond, which improves the holding strength of the bond to the diamond and then the bending strength of the segments. When the volume ratio of binder to Cu-Sn-Ti alloy is 1∶1, there forms a dense glass network in the segments sintered at 950 ℃, with shrinkage of 3% and maximum bending strength of 64.4 MPa.