Fabrication and properties of SiC reinforced graphite composites by hot-pressing sintering
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摘要: 以天然鳞片石墨为起始原料, SiC颗粒为增强相, 采用热压烧结工艺制备了SiC增强石墨复合材料。研究了SiC含量对SiC增强石墨复合材料微观结构、力学性能和摩擦性能的影响。结果表明:SiC颗粒均匀分布在石墨基体中, 降低了基体中的孔隙率;随着SiC含量增加, SiC增强石墨复合材料的相对密度和弯曲强度相应增加, 开孔率显著降低, 当SiC含量达到40vol%时, SiC增强石墨复合材料中形成了SiC网络骨架结构, 相对密度达到了94.2%, 比商品高强纯石墨材料提高了11.8%, 弯曲强度达到了146 MPa, 比商品高强纯石墨材料提高了147%;基体石墨保持了层状结构;SiC含量低于40vol%时, SiC增强石墨复合材料的摩擦系数随SiC含量的增加轻微增加, 与纯石墨材料的摩擦系数相当, 具有良好的摩擦性能。Abstract: SiC reinforced graphite composites were prepared with natural flake graphite as raw materials and SiC particles as reinforcement phase by hot-pressing sintering process. The effects of SiC contents on microstructures, mechanical properties and friction behavior of SiC reinforced graphite composites were analyzed. The results show that the SiC particles are uniformly distributed in graphite matrix, greatly reducing the porosity of matrix. With the increasing of SiC content, relative density and bending strength of SiC reinforced graphite composites increase, and the open porosity falls significantly. The relative density and flexural strength of composites with 40vol% SiC reach 94.2% and 146 MPa due to the formation of SiC network backbone structure in SiC reinforced graphite composites, 11.8% and 147% larger than those of commodity high-strength pure graphite materials. Matrix graphite keeps the layered structure. The friction coefficients of SiC reinforced graphite composites increase slightly with the content of SiC increasing, which keep the same friction coefficient of pure graphite material when the content of SiC is no more than 40vol%, which shows good friction properties.
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Key words:
- SiC /
- graphite /
- hot-pressing sintering /
- composites /
- friction properties
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