Effect of holding time and pressure on properties of ZrB2-SiC composite fabricated by the spark plasma sintering reactive synthesis method

Structure-property relations of ZrB2-SiC composites fabricated by spark plasma sintering reactive synthesis (SPS-RS) method were investigated. The effects of the holding time and pressure on the density, mechanical properties and microstructures were characterized. The results showed that the density increased with both holding time and pressure increased. Hardness was not affected much by the processing condition when the density was above 96.3%. However, fracture toughness values were found to depend on holding time. The value increased from 4.3 ± 0.2 MPa m1/2 to 5.3 ± 0.3 MPa m1/2 when the holding time prolonged from 9 min to 12 min for the grain size of ZrB2 and SiC increased.