Avoiding the oxidation of SiC in SiC-borosilicate glass composites by adding zinc

The oxidation of SiC in SiC-borosilicate glass composites during sintering produces gases, which causes high volume expansion and limits application of the composites in packaging fields. In this study, Zn was added into the composites and SiC was protected by the preferential oxidation of Zn. As Zn was over 6 wt.%, the oxidation resultant of Zn formed gahnite and willemite. Willemite caused thermal stress and decreased the bending strength. The composites with 6 wt.% Zn got minimum volume expansion ratio (−2.3%) and maximum bending strength (75.4 MPa), by contrast, that of the composites without Zn was 36.5% and 16.6 MPa.