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

• ZrB2–SiC powders with different morphologies were synthesized.
• Precipitation and sol–gel methods were used to prepare ZrO2–SiO2 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 ZrB2.

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–SiO2 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.

SEM images of the ZrB2-SiC powders obtained by different methods.Figure optionsDownload as PowerPoint slide