Graphite flake for diamond synthesis and its preparation method

A technology for synthesizing diamond and graphite sheets, applied in the field of diamond synthesis, can solve the problems of increasing the thickness of stamping forming, high cost, low processing yield, etc., to prevent shrinkage cracking, easy to control and improve bulk density, and low cost. Effect

Inactive Publication Date: 2006-05-03
ZHENGZHOU ARTIFICIAL DIAMOND & PROD ENG TECH RES CENT
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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 proces

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  • Graphite flake for diamond synthesis and its preparation method

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Embodiment Construction

[0010] Synthetic graphite flakes for diamond, the preparation of which includes the following steps: (1) taking cooked petroleum coke, cooked pitch coke, natural flake graphite and molten pitch in parts by weight, (2) pretreating cooked petroleum coke and cooked pitch coke— Coarse crushing, calcining, crushing, and grinding to remove volatile matter, (3) adding graphite powder and molten pitch, kneading, rolling and grinding, (4) forming the powder in the mold by two-way isobaric pressing Compact, (5) Roast the compact at 1100-1150°C for 5-7 days to form a carbon rod, the diameter of the carbon rod is 2mm larger than the diamond synthesis cavity, (6) Coke the carbon rod, (7) Coke the carbon rod The carbon rod is heated to 2200-2800 ℃ for graphitization treatment for 15-17 days, (8) the outer circle is turned and sliced. The raw material formula, calcination temperature and time, graphitization temperature and time are shown in Table 1 in each embodiment.

[0011] c...

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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 ...

Claims

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Application Information

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IPC IPC(8): C01B31/04C01B31/06
Inventor 刘杰郭留希赵清国
Owner ZHENGZHOU ARTIFICIAL DIAMOND & PROD ENG TECH RES CENT
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