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

Abstract

ZrB{sub 2}–SiC ceramics, whose SiC is generally incorporated into the system by mechanical mixing, are known to have better performance than monolithic ZrB{sub 2}. Therefore, synthesis of duplex ZrB{sub 2}–SiC powders is beneficial for improving sinterability and mechanical properties of ZrB{sub 2}–SiC composites. In the present work, ZrB{sub 2}–SiC duplex powders with different morphologies were synthesized at 1550 °C for 2 h using as-synthesized amorphous hydrous ZrO{sub 2}–SiO{sub 2}. Both precipitation and sol–gel methods were used to prepare ZrO{sub 2}–SiO{sub 2} precursors. ZrB{sub 2}–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. - Graphical abstract: SEM images of the ZrB2-SiC powders obtained by different methods. Display Omitted - Highlights: • ZrB{sub 2}–SiC powders with different morphologies were synthesized. • Precipitation and sol–gel methods were used to prepare ZrO{sub 2}–SiO{sub 2} precursors. • Possible mechanisms of morphology formation were investigated. • This work provided a potential way of morphology control for raw powders. • The synthesized duplex powders achieved a uniform distribution of SiC in ZrB{sub 2}.