纳米碳化硅对浆料流变学及碳化硅性能的影响
Effects of nano-SiC powder on rheological behavior of SiC slurry and mechanical properties of RBSC
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摘要: 研究纳米碳化硅颗粒对凝胶注浆料流变学特性及反应烧结碳化硅性能的影响.利用凝胶注模(gel-casting)成型工艺制备碳化硅素坯,经过脱模、干燥、预烧结和反应烧结等工艺,制备含有纳米碳化硅颗粒的反应烧结碳化硅(RBSC),总结了固含量、球混时间和纳米碳化硅含量对浆料流变学特性的影响机制.实验结果表明: 加入纳米碳化硅颗粒后,浆料流变学特性由剪切变稀转变为先剪切增稠后剪切变稀.随着纳米碳化硅的加入,反应烧结碳化硅的力学性能不断提高,当纳米碳化硅颗粒含量达到7%时,反应烧结碳化硅的抗弯强度和弹性模量分别提高到345 MPa和339 GPa,与未加纳米碳化硅颗粒相比,分别增加了18.1%和13.8%.纳米碳化硅的加入改变了浆料的流变学特性,提高了反应烧结碳化硅的力学性能.Abstract: The effects of nano-SiC power additive on rheological behavior of SiC slurry and mechanical properties of RBSC were investigated. SiC blanks were prepared with gel-casting method, through drying, burning out the organic elements, infiltrating silicon and reaction sintering, the RBSC with nano-SiC particles were fabricated. Influence of solid loading, ball-milling time and nano-SiC particles on rheological behavior of SiC slurry was discussed. Due to the addition of nano-SiC particles, SiC slurry rheological behavior was changed from shear thinning to first shear thickening, then shear thinning. With 7% nano-SiC powder, the bending strength and elastic modulus of RBSC were elevated to 345 MPa and 339 GPa,respectively increasing by 18.1% and 13.8%. RBSC mechanical properties were improved with the addition of nano-SiC powder.
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