Graphite flake for diamond synthesis and its preparation method

Abstract

The graphite leaf for diamond synthesis belongs to corresponding technical field. Wherein, the preparation method comprises: (1) as weight share, select boiled rock tar 60-70, boiled asphalt tar 20-30, native crystalline flake graphite 1-10 and molten asphalt 8-10 as raw material; (2) to boiled rock tar and boiled asphalt tar, coarse break, calcine, squash and mill to powder; (3) add graphite dust and molten asphalt to mix, roll and mill to powder; (4) use two-way equal-pressure compact method to make powder material into pressed shape; (5) bake the pressed shape for 5-7 days at 1100-1150Deg to form carbon rod with diameter 2mm larger than synthesis diamond cavity; (6) treat the carbon rod by dipping into tar; (7) then heat the rod to 2200-2800Deg for graphitizing 15-17days; bevel out circular, and cut pieces. The product has graphitizing degree 90í‚2%, volume density 2.0í‚0.2g / cm3ú¼ash degree less than 0.01%, and thickness 0.5-1.0mm, for diamond synthesis, which has high conversion rate, concentrated peak particle size, and high yield.

Description

technical field [0001] The invention belongs to the technical field of diamond synthesis, and in particular relates to a graphite sheet suitable for synthesizing diamonds in large tonnage hydraulic presses and large cavities. Background technique [0002] Graphite sheet is the main raw material for diamond synthesis by static pressure catalyst method. It is the only raw material for diamond conversion, the only source of heating element in the synthesis chamber, and the pressure transmission and pressure medium in the high-pressure chamber. Therefore, when synthesizing diamond, the quality of graphite flakes directly affects the nucleation and growth of diamond. As the main raw material for synthetic diamond, the quality of existing graphite flakes cannot meet the production requirements. The main problems are as follows: (1) The degree of graphitization is low and uneven, resulting in unstable synthesis process and low conversion rate ; (2) The bulk density of graphite is ...

AI Technical Summary

Problems solved by technology

As the synthesis cavity increases, the outer diameter of the graphite sheet for synthetic diamond also increases, but the thickness must be kept at about 1.0mm. In the process of powder pressing the graphite sheet, it is necessary to increase the stamping thickness, green body rolling column and grinding sheet process to ensure To overcome the deformation of the blank in high temperature treatment, the processing yield is very low and the cost remains high

For the new large-tonnage six-sided top press, the graphite sheet used to synthesize the Φ30-Φ60mm cavity is less than 1.0mm in thickness, and the manufacturing cost is higher

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