黑滑石高温物相行为变化及其复合材料性能研究

摘要

In the present work the phase behavior of black talc calcined in different temperature and atmosphere was investigated. The graphene reinforced composites was prepared by pressless sintering with the calcined product as raw material. The phase and morphology of the composites were characterized by X-ray diffraction and transmission electron microscopy. The mechanical properties, electrical conductivity and thermal conductivity of the composite samples were measured by electron universal tester, high resistance tester and thermal conductivity coefficient tester, respectively. The results showed that multilayer graphene exists in the calcined products. The existence of graphene has an important influence on the properties of the composites. As far as performance is concerned, the composite samples calcined under nitrogen atmosphere is better than the composite samples calcined under air atmosphere. The average flexural strength of the composites was increased by about 10 MPa, the electrical resistivity decreased about one order of magnitude, and the average thermal conductivity increased by about 6.2×10-1 W/m·K.%以黑滑石为原料,研究了不同温度和气氛下煅烧或炭化过程中的物相行为变化,并以煅烧/炭化产物为原料烧结制备出石墨烯增强顽火辉石基复合材料.采用X射线衍射和透射电子显微技术表征了煅烧产物及复合材料的物相和表面形貌.采用三点弯曲试验机、高电阻测试仪和导热系数测定仪分别测试了复合材料的力学性能、导电和导热性能.结果表明,在氮气气氛下高温处理后的滑石粉中存在多层石墨烯,这对复合材料的性能的提高起到重要的作用.氮气气氛下炭化产物所制备的复合材料较空气气氛下煅烧产物所制得的复合材料而言,其平均抗折强度提高约10 MPa,电阻率低一个数量级,平均导热系数提高了约6.2×10-1 W/(m·K).