The Preparation And Fractal Study Of Graphite Foam

With the rapid development of aviation and space industry, automobile, communication and information industries, it has put forward some more severe requirements in the field of modern materials, such as: erode resistant, mechanical propoerties and high thermal conductivity. In order to meet them, the graphite foam material on behalf of the heat conduction technique with new materials has appeared.The mesophase pith-derived graphite foam is a porous material, which owns the excellent thermal-phsical property of small density and great thermal conductivity. Using the graphite foam material to produce a variety of radiators could greatly decrease the weight and volume of the radiators.In this passage, the author has done a research on the preparation of the graphite foam, and investigated the influence to the structure and property of the porous material under different preparative process conditions. Also according to the pore distribution uniformity coefficient, the author has estimated the porous materials gained by experiment preparation, and optimized the experiment, meanwhile advanced a reference to the estimetion for the similar porous media.In order to research the microstructure of graphite foam, has introduced a fractal theory whose reseach object is just the irregular geometric shape. On the basis of the new type porous materials obtained by experiments, the writer caculated the fractal dimension of its section to establish a material structrue model, a simplified heat-conduction model, and figured out its coefficient of thermal conduction by using the equivalent thermal resistance method. The result shows that the calculated value from this method is inconformity with the reported actual data, which proves the fractal model farily reasonable. Therefore , to some extent such a method owns the guiding significance to the research on the thermal-phsical property of porous materials.