石墨种类对尖晶石碳材料性能与结构的影响

Effect of graphite varieties on properties and structure of spinel carbon materials

以质量分数分别为88%的镁铝尖晶石、8%的石墨、1%的B 4C、3%的铝硅合金粉为原料,外加7%的酚醛树脂和2.5%的酒精制备了尖晶石碳材料,研究了石墨种类(鳞片石墨(+199和-199)、超细鳞片石墨SG、膨胀石墨EG)对该材料性能与结构的影响。结果表明:1、石墨含量至8%(w)时,石墨在基质中的分布不连续。鳞片石墨(+199和-199)对试样抗热震性和常温强度影响不大。加入3%(w)的超细鳞片石墨对试样的抗热震性较佳;2、热震后试样的残余强度随膨胀石墨含量的增加稍有提高,而强度保持率最高试样的常温抗折强度则较低,综合考虑加入1%(w)的膨胀石墨较为适宜;3、尖晶石碳棒头材料中石墨组成为鳞片石墨(+199和-199)和膨胀石墨,制备了多支塞棒进行了工业试验,结果表明该塞棒棒头不开裂,抗冲刷性能较好。

The spinel carbon materials were prepared using 88 mass%of MgO-Al 2O3 spinel,8 mass%of graphite,1 mass%of B 4C and 3 mass%of Ai-Si alloy powder as the starting materials,extra-adding 7 mass%of phenolic resin and 2.5 mass%of alcohol as the binder.Effect of different graphite varieties(flake graphite(+199 and-199),ultra-fine flake graphite(SG),expanded graphite(EG))on the properties and structure of spinel carbon materials was researched.The results show that:(1)the distribution of graphite in the matrix is discontinuous when the graphite content is 8%,and the flake graphites(+199 and-199)have little effect on the thermal shock resistance and cold strength of spinel carbon materials,and with 3%ultra-fine flake graphite,the material performs the optimal thermal shock resistance;(2)the residual strength after thermal shock of spinel carbon materials slightly increases with the increase of expanded graphite content,however,the specimen with the highest strength retention ratio has lower cold modulus of rupture;according to overall consideration,adding 1%expanded graphite is suitable;(3)the head of stoppers with graphite composition of crystalline flake graphite(+199 and-199)and expanded graphite were prepared and used for the industrial test,the service results show that the stoppers don’t crack and have good erosion resistance.