A split core column for diamond synthesis and its preparation method

Abstract

The invention discloses a splitting core column for synthesizing diamond and a preparation method thereof. The splitting core column for synthesizing the diamond comprises a core column tube, wherein a core column is arranged in the core column tube, a first core column piece is arranged on the upper end of the core column tube, and a second core column piece is arranged on the lower end of the core column tube. According to the splitting core column for synthesizing the diamond, different mixing ratios of peripheral materials to internal materials are adopted, and the weight ratio of catalysts of the peripheral materials is controlled to be higher than that of the core column by 4% to 8%, so as to effectively control the granularity of the peripheral materials, thereby reducing the growth rate of the peripheral materials, so that the whole core column for synthesis grows at uniform speed in the process that graphite is converted into the diamond, and the granularity of the synthesized diamond is uniform; the isostatic pressing granulation granularity range of the core column pieces and the core column tube and the isostatic pressing granulation granularity range of the core column are controlled, so that materials are uniformly fed into a die cavity during pressing, and the density of pressed products of the core column pieces, the core column tube and the core column is uniform, thereby guaranteeing the quality and the yield of the synthesized diamond.

Description

Technical field

[0001] The invention relates to the technical field of diamond synthesis, in particular to a split core column for diamond synthesis and a preparation method thereof. Background technique

[0002] In the synthesis of synthetic diamond, the graphite in the top press is converted into diamond by a six-side top press under a constant ultra-high temperature and high pressure. Therefore, the core column of the synthesized diamond is the place where the diamond grows. When synthesizing, six blocks are synthesized. The directionally balanced force makes the inside of the synthesis cavity obtain a stable pressure field distribution, but from the outside to the inside, there is an obvious pressure gradient field, which directly affects the quality of the synthetic material, and there are problems such as low diamond output and low heat utilization efficiency. This is because the current synthetic diamond core column is an integrated column with a single formula. The pressu...

Examples

preparation example Construction

[0043] The invention also relates to a method for preparing a split core column for diamond synthesis, the steps are as follows:

[0044] (1) Mix the graphite powder and catalyst powder according to the weight ratio of 30-65% of the catalyst powder in the raw material of the core column 4, add them to the mixer and mix for 3 to 5 hours, mix the materials thoroughly, and obtain the mixture a;

[0045] (2) The graphite powder and the catalyst powder are mixed according to the weight ratio of the catalyst powder in the raw materials on the periphery of the core column 4, and the weight ratio of the catalyst powder in the raw materials on the periphery of the core column 4 is higher than that in step (1) The weight ratio of the catalyst powder in the raw materials is 4~8% higher, and it is added to the mixer and mixed for 3~5h to make the materials fully mixed to obtain the mixture b;

[0046] (3) The mixture a obtained in step (1) is subjected to cold isostatic pressing to form blocks a...

Embodiment 1

[0065] A split core column for diamond synthesis, comprising a core column tube 3, a core column 4 is arranged in the core column tube 3, a first core column sheet 1 is arranged at the upper end of the core column tube 3, and a second core column is arranged at the lower end of the core column tube 3 Sheet 2, the diameter of the first core pillar sheet 1, the diameter of the second core pillar sheet 2 and the outer diameter of the stem tube 3 are the same, the thickness of the first core pillar sheet 1 and the thickness of the second core pillar sheet 2 and the core pillar The wall thickness of the tube 3 is the same, and the ratio of the wall thickness of the core column tube 3 to the diameter of the core column 4 is 1:1; the periphery of the core column 4 and the raw materials of the core column 4 are composed of catalyst powder and graphite powder, and the raw material of the core column 4 The weight ratio of the catalyst powder in the core column 4 is 30%, and the weight rat...

Embodiment 2

[0067] A split core column for diamond synthesis, comprising a core column tube 3, a core column 4 is arranged in the core column tube 3, a first core column sheet 1 is arranged at the upper end of the core column tube 3, and a second core column is arranged at the lower end of the core column tube 3 Sheet 2, the diameter of the first core pillar sheet 1, the diameter of the second core pillar sheet 2 and the outer diameter of the stem tube 3 are the same, the thickness of the first core pillar sheet 1 and the thickness of the second core pillar sheet 2 and the core pillar The wall thickness of the tube 3 is the same, and the ratio of the wall thickness of the core column tube 3 to the diameter of the core column 4 is 1:3; the periphery of the core column 4 and the raw materials of the core column 4 are composed of catalyst powder and graphite powder, and the raw material of the core column 4 The weight ratio of the catalyst powder in the core column 4 is 65%, and the weight rat...

Technical field

[0001] The invention relates to the technical field of diamond synthesis, in particular to a split core column for diamond synthesis and a preparation method thereof. Background technique

[0002] In the synthesis of synthetic diamond, the graphite in the top press is converted into diamond by a six-side top press under a constant ultra-high temperature and high pressure. Therefore, the core column of the synthesized diamond is the place where the diamond grows. When synthesizing, six blocks are synthesized. The directionally balanced force makes the inside of the synthesis cavity obtain a stable pressure field distribution, but from the outside to the inside, there is an obvious pressure gradient field, which directly affects the quality of the synthetic material, and there are problems such as low diamond output and low heat utilization efficiency. This is because the current synthetic diamond core column is an integrated column with a single formula. The pressu...

Examples

preparation example Construction

[0043] The invention also relates to a method for preparing a split core column for diamond synthesis, the steps are as follows:

[0044] (1) Mix the graphite powder and catalyst powder according to the weight ratio of 30-65% of the catalyst powder in the raw material of the core column 4, add them to the mixer and mix for 3 to 5 hours, mix the materials thoroughly, and obtain the mixture a;

[0045] (2) The graphite powder and the catalyst powder are mixed according to the weight ratio of the catalyst powder in the raw materials on the periphery of the core column 4, and the weight ratio of the catalyst powder in the raw materials on the periphery of the core column 4 is higher than that in step (1) The weight ratio of the catalyst powder in the raw materials is 4~8% higher, and it is added to the mixer and mixed for 3~5h to make the materials fully mixed to obtain the mixture b;

[0046] (3) The mixture a obtained in step (1) is subjected to cold isostatic pressing to form blocks a...

Embodiment 1

[0065] A split core column for diamond synthesis, comprising a core column tube 3, a core column 4 is arranged in the core column tube 3, a first core column sheet 1 is arranged at the upper end of the core column tube 3, and a second core column is arranged at the lower end of the core column tube 3 Sheet 2, the diameter of the first core pillar sheet 1, the diameter of the second core pillar sheet 2 and the outer diameter of the stem tube 3 are the same, the thickness of the first core pillar sheet 1 and the thickness of the second core pillar sheet 2 and the core pillar The wall thickness of the tube 3 is the same, and the ratio of the wall thickness of the core column tube 3 to the diameter of the core column 4 is 1:1; the periphery of the core column 4 and the raw materials of the core column 4 are composed of catalyst powder and graphite powder, and the raw material of the core column 4 The weight ratio of the catalyst powder in the core column 4 is 30%, and the weight rat...

Embodiment 2

[0067] A split core column for diamond synthesis, comprising a core column tube 3, a core column 4 is arranged in the core column tube 3, a first core column sheet 1 is arranged at the upper end of the core column tube 3, and a second core column is arranged at the lower end of the core column tube 3 Sheet 2, the diameter of the first core pillar sheet 1, the diameter of the second core pillar sheet 2 and the outer diameter of the stem tube 3 are the same, the thickness of the first core pillar sheet 1 and the thickness of the second core pillar sheet 2 and the core pillar The wall thickness of the tube 3 is the same, and the ratio of the wall thickness of the core column tube 3 to the diameter of the core column 4 is 1:3; the periphery of the core column 4 and the raw materials of the core column 4 are composed of catalyst powder and graphite powder, and the raw material of the core column 4 The weight ratio of the catalyst powder in the core column 4 is 65%, and the weight rat...

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