Effect of Sintering Temperature on Properties of Fused Silica- YSZ Composite Prepared by Spark Plasma Sintering

In this research, fused silica-zirconia composites including of 5 % by weight of zirconia stabilized yettria prepared by Spark Plasma Sintering (SPS) method. The powders were mixed by Spex (8000D, High energy ball mill) for 30 min in ethanol media. After mixing process, the ethanol removed by heating of the batches at 70 °C. The prepared samples were sintered at 1100, 1200 and 1300 °C and final pressure of 30 MPa. FESEM images demonstrated distribution of reinforcements at the fused silica matrix, also the results showed that sintered samples at 1200 °C have better properties than other samples. Relative density, flexural strength, hardness and toughness of these samples were 99.99 %, 13.4 GPa, 131 MPa and 4.46 MPa.m1/2 respectively. Also results showed that with increasing of sintering temperature to 1300 °C, due to crystallization in fused silica and as a result the formation of cracks in matrix, flexural strength decreased but the hardness and toughness increased slightly.