【摘要】 分别采用骨料/黏结剂二元法和中间相炭微球单相自烧结法制备了细颗粒等静压石墨。以煤沥青为黏结剂，平均粒径分别为10μm和5μm的沥青焦为骨料制备等静压石墨，标记为G1和G2;以平均粒径为5μm的中间相炭微球为原料，制备等静压石墨，标记为G3。研究了原料种类和颗粒尺寸对石墨材料微观结构、孔隙结构、晶体参数和热力学性能等的影响。骨料的粒径减小，能够有效地降低石墨材料结构内部的孔隙/缺陷尺寸，并提高材料的力学强度；G2石墨的平均孔径为0.527μm,远低于G1石墨的1.620μm,其抗折和抗压强度分别达到84 MPa和142 MPa。然而，较小的骨料粒径会降低石墨的结晶程度和晶粒尺寸，从而不利于其热性能的提升。采用平均粒径5μm的中间相炭微球试制的G3石墨具有非常优异的机械性能，抗折强度高达96 MPa,平均孔径仅为0.071μm,而石墨化度和晶粒尺寸L_a分别为71.5%和38.8 nm,石墨的常温热导率仅有47 W/(m·K)。更多还原

【Abstract】 Fine-grained isostatic-pressing graphites were prepared by liquid mixing method and self-sintering method, respectively.G1 and G2 graphites were prepared by liquid mixing method using the calcined pitch coke aggregates with the average diameters of 10 μm and 5 μm, respectively.G3 graphite was fabricated by mesocarbon microbeads with the average diameters of 5 μm using self-sintering method.Microstructure, porosity, pore size distribution, crystal structure and thermophysical properties of the obtained graphites were systematically studied.Results indicate that the mean pore size of graphite could be adjusted by changing the filler particle size distribution.G2 graphite possesses excellent properties such as high bending strength of 84 MPa, compressive strength of 142 MPa and an average pore diameter of 0.527 μm.However, with the decrease of coke fillers size, both the graphitization degree and crystallite diameter L_a are decreased.The bending strength and pore size distribution of G3 graphite are 96 MPa and 0.071 μm, respectively.Due to the lower graphitization degree(71.5%) and smaller crystallite diameter(L_a=38.8 nm) of MCMBs, the thermal conductivity of G3 graphite is limited to 47 W/(m·K),much lower than those of other graphites.更多还原