High-strength and high-density graphite material and preparation method

Abstract

The invention relates to a high-strength and high-density graphite material and a preparation method. The preparation method includes the steps of S1, using an organic solvent to dissolve soft asphalt to obtain a soft asphalt solution, using the soft asphalt solution to spray calcined fine coke powder, and mechanically mixing into isotropic asphalt powder to obtain a mixture; S2, performing compression molding on the mixture to obtain a green body, calcining the green body once, using impregnation asphalt to perform density increasing, and performing second calcining and graphitizing to obtain the high-density graphite material. The preparation method has the advantages that the surface of the calcined coke powder can be moistened and even in soft asphalt coating by the liquid spraying technology, and the interface compatibility and isotropic degree of the coke powder are increased; the isotropic asphalt can be evenly decomposed during the calcining, the calcined isotropic asphalt and the coke powder aggregate are consistent in shrinkage, material internal stress is relieved, and yield is increased evidently; the high-strength and high-density graphite material is prepared by one impregnation, two calcinations and one graphitizing, and the method is simple in process, low in cost, good in repeatability and short in production cycle.

Description

technical field [0001] The invention belongs to the field of graphite materials, and in particular relates to a high-strength and high-density graphite material and a preparation method thereof. Background technique [0002] Graphite materials, especially high-strength and high-density isotropic graphite, have the characteristics of small specific gravity, high mechanical strength, good electrical and thermal conductivity, high temperature resistance, corrosion resistance, self-lubrication, etc., and are widely used in semiconductor industry, photovoltaic industry, EDM, metal Continuous casting, optical fiber, mold manufacturing, aerospace and nuclear industries are irreplaceable new materials that are closely related to the development of today's high technology, and their development is rapid and in the ascendant. [0003] At present, the methods for preparing high-strength and high-density graphite materials are generally divided into traditional methods and self-sinterin...

AI Technical Summary

Problems solved by technology

The traditional method uses high-temperature calcined coke (petroleum coke or pitch coke) fine powder as the aggregate, pitch or resin as the binder, and after mixing (hot kneading, hot rolling, and grinding) to make it uniform, use cold Molding or cold isostatic pressing, repeated roasting-impregnation and densification, and finally graphitization treatment, the production cycle of this method is as long as half a year, the production efficiency is low, and the energy consumption is large. Although the cost of raw materials is low, but The time cost is high, and the semi-finished product is easily damaged and cracked after repeated dipping and roasting treatment, forming uneven material, which affects the mechanical properties of the final product, and the product size is limited to a certain extent

Although the hot isostatic pressing process can improve the production efficiency, the production equipment is expensive, the process operation is difficult, and it is impossible to produce large-size graphite products

The self-sintering method uses the self-sintering of raw materials (such as raw petroleum coke powder, mesophase carbon microspheres, insoluble pitch powder, etc.) to form at one time, then roast, and finally graphitize to obtain high-strength and high-density graphite materials without the need for additional binders. To assist sintering, its production process is relatively simple, but the self-sintering components of raw materials (related to volatile components) are generally difficult to accurately adjust and stably control (usually "moderate" pre-oxidation or non-melting treatment), thus affecting the size of the product, Physical Properties and Yield