微热压制备石墨碳化硅陶瓷复合材料

Graphite Silicon Carbide Ceramic Composite Made Using Micro-Hot Pressing Additive

以天然鳞片石墨粉末为原材料、热固性酚醛树脂为黏结剂,基于微热压技术原理实现了石墨碳化硅陶瓷复合材料快速制备,重点研究混合粉末组成对其抗压强度、导热性能的影响。研究结果表明,当天然鳞片石墨粉末质量分数为85%、热固性酚醛树脂质量分数为15%,高纯硅粉、短切碳纤维、中间碳微球质量分数分别为25%、4%、21%时,石墨碳化硅陶瓷复合材料抗压强度、导热系数分别达到30.82 MPa、21.65 W/m·K;并测试其热膨胀系数和抗氧化性能,在1200℃条件下,其氧化失重为23.679%、热膨胀系数为3.14×10^(-6)K^(-1)。该复合材料有望代替石墨铸型材料,在铸造行业获得应用。

In this paper,based on the principle of micro-hot pressing additive manufacturing technology,rapid preparation of graphite silicon carbide ceramic composites is achieved,using natural flake graphite powder as the raw material and thermosetting phenolic resin as the adhesive.Particular focus is placed on the composition of mixed powder,and how this affects its compressive strength and thermal conductivity.The results show that when the natural flake graphite powder and the thermosetting phenolic resin is fixed at 85% and 15%,respectively,the mass fractions of high purity silica powder,short carbon fiber,and intermediate carbon microspheres is 25%,4% and 21%,respectively.The compressive strength and thermal conductivity of the graphite silicon carbide ceramic composite is 30.82 MPa and 21.65 W/m·K,respectively.By testing the thermal expansion coefficient and oxidation resistance of the composite at 1200℃,the oxidation weight loss and the thermal expansion coefficient is determined to be 23.679% and 3.14×10^(-6)/K,respectively.This composite material is expected to replace graphite casting and be applied in the casting industry.