Synthesis of ZrB2–SiC–ZrC nanocomposite by spark plasma in ZrSiO4/B2O3/C/Mg system

Abstract

A novel reduction process by spark plasma is proposed for the synthesis of homogeneous intermixed ZrB2–SiC–ZrC nanostructure powder using ZrSiO4, B2O3, C and Mg as starting materials. In the present research, the reaction mechanisms were investigated by the displacement–temperature–time (DTT), the displacement rate–temperature and the displacement rate–time diagrams which were obtained during spark plasma cycles. The synthesis process of the composite was completed after 15min at temperature of 400°C. The total shrinkage of 5.5mm was observed due to the rearrangement and reaction phenomenon. The main shrinkage occurs within a period of less than 1min at 400°C similar to the self propagating high temperature synthesis. Finally using Rietveld method, the mean crystallites sizes of about 26, 25 and 22nm were calculated for ZrB2, SiC and ZrC phases, respectively.