Morphology and mechanism study for the synthesis of ZrB₂-SiC powders by different methods

ZrB₂-SiC ceramics, whose SiC is generally incorporated into the system by mechanical mixing, are known to have better performance than monolithic ZrB₂. Therefore, synthesis of duplex ZrB₂-SiC powders is beneficial for improving sinterability and mechanical properties of ZrB₂-SiC composites. In the present work, ZrB₂-SiC duplex powders with different morphologies were synthesized at 1550 C for 2 h using as-synthesized amorphous hydrous ZrO₂-SiO₂. Both precipitation and sol-gel methods were used to prepare ZrO₂-SiO ₂ precursors. ZrB₂-SiC powder derived from precipitation method presented a rod-like morphology with smaller irregular particles adhering to them. And the morphology from sol-gel method was equiaxed shape with a very uniform distribution for principal components of Zr and Si.