Influence of Al2O3 on the structure and the physical properties of low-temperature ceramic vitrified bond

The SiO2-B2O3-Al2O3-CaO vitrified bonds with low sintering temperatures and high strength are widely used in the manufacture of diamond abrasive tools. The effects of Al2O3 on the microstructure, crystallization, phase-separated and mechanical properties were comprehensively investigated by DSC, FTIR, XRD, SEM and EDS in this paper. The results showed that the addition of Al2O3 promoted the accumulation and enhanced the binding of structure, inhibited crystallization and phase-separated. Performance analysis showed that the thermal expansion coefficients decreased with increasing Al2O3 content, the minimum value was 6.8074×10−6 °C−1. When the content of Al2O3 was 5 wt%, the vitrified bond had the best mechanical properties, the maximum bending strength reached 113 MPa and effectively improved the wettability between vitrified bond and diamond grains.