The effects of metallic Si addtions on the synthesis of β-SiC powders using a sol-gel method

The effects of metallic Si addtions on the synthesis of β-SiC powders using a sol-gel method

Single phase β-SiC powders were synthesized using SiO2/C hybrid precursors with and without the addition of metallic Si powders. The SiO2/C hybrid precursors with various C/Si mole ratios (1.6-4.0) were prepared by a sol-gel process using tetraethyl orthosilicate and phenol resin as starting materials. Fine β-SiC powders were synthesized by the carbothermal reduction of the SiO2/C hybrid precursor with and without the addition of metallic Si powders in the temperature range between 1250 oC-1800 oC under a vacuum atmosphere. Single phase β-SiC powders were obtained by the carbothermal reduction of the SiO2/C hybrid precursor with a C/Si mole ratio of 1.6 above 1600 oC under a vacuum atmosphere. It was found that the addition of metallic Si powders to the the SiO2/C hybrid precursor with excess carbon reduced the temperature for the synthesis of single phase β-SiC powders to as low as 1350 oC. The particle sizes of synthesized β-SiC powders from the metallic Si powder added SiO2/C hybrid precursor with excess carbon were less than 1 μm, in which fine β-SiC powders appeared to be slightly aggregated.

Single phase β-SiC powders were synthesized using SiO2/C hybrid precursors with and without the addition of metallic Si powders. The SiO2/C hybrid precursors with various C/Si mole ratios (1.6-4.0) were prepared by a sol-gel process using tetraethyl orthosilicate and phenol resin as starting materials. Fine β-SiC powders were synthesized by the carbothermal reduction of the SiO2/C hybrid precursor with and without the addition of metallic Si powders in the temperature range between 1250 oC-1800 oC under a vacuum atmosphere. Single phase β-SiC powders were obtained by the carbothermal reduction of the SiO2/C hybrid precursor with a C/Si mole ratio of 1.6 above 1600 oC under a vacuum atmosphere. It was found that the addition of metallic Si powders to the the SiO2/C hybrid precursor with excess carbon reduced the temperature for the synthesis of single phase β-SiC powders to as low as 1350 oC. The particle sizes of synthesized β-SiC powders from the metallic Si powder added SiO2/C hybrid precursor with excess carbon were less than 1 μm, in which fine β-SiC powders appeared to be slightly aggregated.