▎ 摘　　要

NOVELTY - Preparing carbon modified nano silicon carbide composite material involves ball-milling and mixing the silicon carbide precursor, the pretreated silicon carbide precursor and the nano carbon material to prepare mixed powder, the silicon carbide precursor is selected from polycarbosilane or a mixture of polycarbosilane and divinylbenzene, and the mass percentage of the divinylbenzene in the mixture is not more than 20%, the pretreatment of the silicon carbide precursor is to carry out heat treatment on the silicon carbide precursor for 3-5 h at 200-500℃ in vacuum or inert gas. In the mixed powder, the mass ratio of an untreated silicon carbide precursor to a pretreated silicon carbide precursor is 1/5-1/3. USE - Method for preparing carbon modified nano silicon carbide composite material used as a radiation detector material (claimed). ADVANTAGE - The method provides carbon-modified nano-silicon carbide composite material with good anti-radiation performance. The obtained material satisfies a new generation of radiation detector in future nuclear application (high temperature, high dose). DETAILED DESCRIPTION - Preparing carbon modified nano silicon carbide composite material involves ball-milling and mixing the silicon carbide precursor, the pretreated silicon carbide precursor and the nano carbon material to prepare mixed powder, the silicon carbide precursor is selected from polycarbosilane or a mixture of polycarbosilane and divinylbenzene, and the mass percentage of the divinylbenzene in the mixture is not more than 20%, the pretreatment of the silicon carbide precursor is to carry out heat treatment on the silicon carbide precursor for 3-5 h at 200-500℃ in vacuum or inert gas. In the mixed powder, the mass ratio of an untreated silicon carbide precursor to a pretreated silicon carbide precursor is 1/5-1/3, the volume percentage of the nano carbon material in the carbon modified nano silicon carbide composite material is less than 6.4 percent, pressing the mixed powder into a green body, crosslinking and curing the green body under vacuum or inert gas, and then cracking the green body at 900-1600℃.