WU Xiaowen, ZHANG Hang, ZHANG Zhijie, HUANG Zhaohui, MIN Xin, FANG Minghao, LIU Yangai

(Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes,National Laboratory of Mineral Materials,

School of Materials Science and Technology,China University of Geosciences (Beijing), Beijing, 100083, China,)

Abstract: 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.

Key words: black talc; graphene; thermal conductivity; flexural strength; resistivity; thermal conductivity