An assembled cavity structure of synthetic PCBN-PCD material

Abstract

The invention discloses an assembled cavity structure for synthesizing PCBN-PCD materials, comprising a core body, a heating system, an upper end plug, a lower end plug and an outer sleeve, wherein the outer sleeve is a cylindrical structure with two ends opened, the core body is located at the axial center of the outer sleeve, the outer surface of the core body wraps the heating system, the two ends of the outer sleeve are respectively sealed with an upper end plug and a lower end plug, the inner ends of the upper end plug and the lower end plug are respectively in extrusion contact with the heating system at the corresponding position, the assembled cavity structure for synthesizing PCBN-PCD materials improves the heating efficiency, maximizes the use of the internal space of the cavity, can solve the problem of uniformity of pressure field and temperature field in the synthesis cavity, improves the production quality of PCBN / PCD, and can increase the sealing of the cavity through the insulating cup in the middle of the ring, and prevents pyrophyllite and graphite tube from penetrating into the synthetic core column to cause pollution during the synthesis of the PCBN / PCD materials, thereby improving the quality of the PCBN / PCD materials.

Description

Technical Field

[0001] The invention relates to the technical field of PCBN / PCD materials, in particular to an assembled cavity structure of a synthetic PCBN-PCD material. Background Art

[0002] In the sintering synthesis process of superhard materials such as polycrystalline cubic boron nitride (PCBN) and polycrystalline diamond (PCD), it is necessary to assemble cubic boron nitride or diamond and a certain amount of binder powder into a closed cavity of pyrophyllite, and a six-sided hydraulic press provides a high-pressure and high-temperature sintering environment for the assembly. In order to obtain this high-pressure and high-temperature synthesis condition, a six-sided hydraulic press is generally used to provide high pressure through six carbide top hammers, and a closed cavity is composed of pyrophyllite, dolomite, steel ring and graphite matrix. The powder is placed in the graphite matrix. Graphite not only serves as a heating body to provide a high-temperature environment, but also as a pressure transmission medium.

[0003] First, under high pressure and high temperature conditions, graphite will undergo elastic deformation, resulting in pressure loss in the synthesis cavity. On the other hand, when the powder raw materials undergo physical and chemical reactions under high pressure and high temperature conditions, graphite and its impurities can easily penetrate and contaminate the raw materials. Secondly, due to the change in volume in the cavity and the heat loss at the end, the pressure field and temperature field inside the cavity are uneven, and the larger the cavity, the higher the degree of unevenness. This directly causes the instability of the quality of the synthesized PCBN / PCD products. In addition, the existing polycrystalline synthesis cavity assembly structure is complex and has poor practicality. During high temperature and high pressure synthesis, the current is directly heated by the synthesis core column, which will have an adverse effect on the synthesis quality of PCBN / PCD. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the existing defects and provide an assembly cavity structure for synthesizing PCBN-PCD materials. Through a dual heating system, the heating efficiency is improved, and the uniformity of the pressure field and temperature field in the synthesis cavity is solved at the same time, which can effectively solve the problems in the background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an assembled cavity structure of a synthetic PCBN-PCD material, comprising a core, a heating system, an upper end plug, a lower end plug and a jacket, wherein the jacket is a cylindrical structure with two ends open, the core is located at the center of the axis of the jacket, the heating system is wrapped around the outside of the core, and the upper end plug and the lower end plug are respectively sealed at both ends of the jacket, the inner ends of the upper end plug and the lower end plug are respectively in extrusion contact with the heating system at the corresponding position, and the vertical outer side wall of the heating system is in contact with the inner wall of the jacket;

[0006] The heating system includes a first heating system and a second heating system, the first heating system includes a graphite heating cup and a first heating sheet, the graphite heating cup is wrapped outside the core body, the first heating sheet is fixedly arranged at the upper and lower ends of the graphite heating cup, the second heating system includes a second heating plate and a graphite tube, the graphite tube is wrapped outside the first heating system, and the second heating sheets are sealed at both ends of the graphite tube, and the surfaces of the first heating sheet and the second heating sheet at the same end are in contact with each other;

[0007] The upper end plug and the lower end plug both include conductors that are connected to the heating system.

[0008] As a preferred technical solution of the present invention, a ceramic tube and an insulating cup are coaxially fitted between the graphite heating cup and the vertical wall of the graphite tube, the ceramic tube is coaxially fitted with the outer wall of the graphite heating cup, the insulating cup is coaxially fitted with the inner wall of the graphite tube, and the magnesium oxide tube is coaxially fitted on the outer wall of the graphite tube.

[0009] As a preferred technical solution of the present invention, the upper end plug includes a conductive doctor's hat steel ring and a conductive bowl-type steel ring, the vertical side wall end of the conductive bowl-type steel ring is in contact with and conductive to the plane part of the conductive doctor's hat steel ring, the conductive bowl-type steel ring is filled with talc sheets, the vertical sleeve of the conductive doctor's hat steel ring is filled with ceramic sheets, and the vertical sleeve of the conductive doctor's hat steel ring is coaxially fixed with a dolomite ring and a talc ring from the end to the bottom in sequence. The lower end plug and the upper end plug have the same structure, the talc rings of the lower end plug and the upper end plug are respectively squeezed into contact with the second heating plate at the corresponding position, and the vertical sleeve ends of the conductive doctor's hat steel ring in the lower end plug and the upper end plug are in contact with and conductive to the second heating plate at the corresponding position.

[0010] As a preferred technical solution of the present invention, the outer sleeve comprises a sealing layer and a pyrophyllite layer coaxially arranged from the inside to the outside, and the inner wall of the sealing layer is in compression contact with the vertical outer side wall of the heating system.

[0011] As a preferred technical solution of the present invention, the core body includes two groups of metal cups with openings on one side and the openings facing each other, and the closed space surrounded by the two groups of metal cups is filled with powder core columns.

[0012] As a preferred technical solution of the present invention, the graphite heating cup is composed of two groups of graphite cups with single-side openings and the openings are opposite to each other, and the insulating cup is composed of two groups of insulating cup bodies with single-side openings and the openings are opposite to each other. A through hole is set at the bottom of the insulating cup body, and the first heating plate is fixedly set in the through hole.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. The present invention improves the conductive efficiency by assembling and matching the conductive bowl-shaped steel ring and the conductive doctor's cap steel ring in the end plug, and overcomes the disadvantage of pressure loss caused by inserting too many graphite sheets in the existing synthesis cavity. The structure with the conductive bowl-shaped steel ring outside and the conductive doctor's cap steel ring inside provides a stable sealing environment, so it is more suitable for the synthesis of PCBN / PCD materials.

[0015] 2. The present invention forms a dual heating system through the first and second heating plates, the graphite tube, and the graphite heating cup, which can overcome the disadvantage of the existing synthesis cavity that the current directly passes through the polycrystalline powder core column for heating, which has an adverse effect on the synthesis quality of PCBN / PCD. It can solve the problem that in the heating process of the ordinary synthesis cavity, the temperature in the center of the cavity is higher and the temperature at both ends is lower, resulting in uneven overall heating and reduced product quality, thereby improving the production quality of PCBN / PCD.

[0016] 3. The present invention can increase the sealing performance of the cavity and the pressure transmission in the cavity through the magnesium oxide tube and the ceramic tube, provide a uniform pressure field and temperature field, and improve the quality of PCBN / PCD products and process stability.

[0017] 4. The present invention can completely wrap and seal the cubic boron nitride or diamond initial raw material core column through the metal cup to prevent impurities from entering, ensure the purity of the initial raw material, reduce the risk of gas cannon in the high-pressure cavity due to the high-pressure and high-temperature violent reaction in the cavity, and improve product quality and synthesis safety factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the core body and the heating system of the present invention combined;

[0020] Figure 3 This is a schematic diagram of the upper end plug of the present invention;

[0021] Figure 4 It is a schematic diagram of the metal cup of the present invention;

[0022] Figure 5 This is a schematic diagram of a graphite heating cup of the present invention;

[0023] Figure 6 It is a schematic diagram of the insulating cup of the present invention.

[0024] In the figure: 1 core body, 101 powder core column, 102 metal cup, 2 heating system, 201 graphite heating cup, 202 first heating plate, 203 second heating plate, 204 graphite tube, 205 ceramic tube, 206 insulating cup, 207 magnesium oxide tube, 3 upper end plug, 301 conductive doctor hat steel ring, 302 conductive bowl-type steel ring, 303 pyrophyllite sheet, 304 pyrophyllite ring, 305 dolomite ring, 306 ceramic sheet, 4 lower end plug, 5 outer jacket, 501 sealing layer, 502 pyrophyllite layer. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] See also Figure 1-6 The present invention provides a technical solution: an assembled cavity structure of a synthetic PCBN-PCD material, comprising a core 1, a heating system 2, an upper end plug 3, a lower end plug 4 and a jacket 5, wherein the jacket 5 is a cylindrical structure with two ends opened, the core 1 is located at the center of the axis of the jacket 5, the heating system 2 is wrapped around the outside of the core 1, and the upper end plug 3 and the lower end plug 4 are respectively sealed at both ends of the jacket 5, the inner ends of the upper end plug 3 and the lower end plug 4 are respectively pressed and contacted with the heating system 2 at the corresponding position, and the vertical outer side wall of the heating system 2 is in contact with the inner wall of the jacket 5;

[0027] The heating system 2 includes a first heating system and a second heating system. The first heating system includes a graphite heating cup 201 and a first heating plate 202. The graphite heating cup 201 is wrapped around the outside of the core 1. The first heating plate 202 is fixedly arranged at the upper and lower ends of the graphite heating cup 201. The second heating system includes a second heating plate 203 and a graphite tube 204. The graphite tube 204 is wrapped around the outside of the first heating system. The second heating plates 203 are sealed at both ends of the graphite tube 204. The surfaces of the first heating plate 202 and the second heating plate 203 at the same end are in contact with each other.

[0028] The upper end plug 3 and the lower end plug 4 both include conductors that are connected to the heating system 2 .

[0029] A ceramic tube 205 and an insulating cup 206 are coaxially fitted between the vertical walls of the graphite heating cup 201 and the graphite tube 204. The ceramic tube 205 is coaxially fitted with the outer wall of the graphite heating cup 201. The insulating cup 206 is coaxially fitted with the inner wall of the graphite tube 204. A magnesium oxide tube 207 is coaxially fitted on the outer wall of the graphite tube 204.

[0030] The upper end plug 3 includes a conductive doctor's hat steel ring 301 and a conductive bowl-shaped steel ring 302. The vertical side wall end of the conductive bowl-shaped steel ring 302 is in contact with and conductive to the plane part of the conductive doctor's hat steel ring 301. The conductive bowl-shaped steel ring 302 is filled with phyllite sheets 303. The vertical sleeve of the conductive doctor's hat steel ring 301 is filled with ceramic sheets 306. The vertical sleeve of the conductive doctor's hat steel ring 301 is coaxially fixed with dolomite rings 305 and phyllite rings 304 in sequence from the end to the bottom. The lower end plug 4 and the upper end plug 3 have the same structure. The phyllite rings 304 of the lower end plug 4 and the upper end plug 3 are respectively pressed and contacted with the second heating plate 203 at the corresponding position. The vertical sleeve ends of the conductive doctor's hat steel ring 301 in the lower end plug 4 and the upper end plug 3 are in contact with and conductive to the second heating plate 203 at the corresponding position.

[0031] The outer sleeve 5 includes a sealing layer 501 and a pyrophyllite layer 502 which are coaxially arranged from the inside to the outside. The inner wall of the sealing layer 501 is in compression contact with the vertical outer side wall of the heating system 2.

[0032] The core body 1 includes two groups of metal cups 102 with openings on one side and facing each other. The closed space surrounded by the two groups of metal cups 102 is filled with powder core columns 101, which effectively reduces the pollution of harmful gases and impurities in the cavity.

[0033] The graphite heating cup 201 is composed of two groups of graphite cups with single-side openings facing each other, and the insulating cup 206 is composed of two groups of insulating cup bodies with single-side openings facing each other. A through hole is set at the bottom of the insulating cup body, and the first heating plate 202 is fixedly set in the through hole.

[0034] To improve heating efficiency, the thickness of the conductive bowl-shaped steel ring 302 is 4-8 mm, and the thickness of the conductive doctor hat steel ring 301 is 6-12 mm;

[0035] In order to improve the pressure transmission and heat preservation effects, the material of the second heating plate 203 is a mixture of two or more of graphite, magnesium oxide, zirconium oxide, dolomite and perovskite oxide, and the thickness of the second heating plate 203 is 1-3 mm;

[0036] In order to achieve dual heating effect, the thickness of the graphite tube 204 and the graphite heating cup 201 are both 0.5-1.5 mm;

[0037] In order to achieve the functions of pressure transmission and heat preservation, the thickness of the magnesium oxide tube 207 and the ceramic tube 205 is 0.5-1.8 mm;

[0038] In order to provide an isolation effect, the material of the metal cup 102 is preferably one of zirconium, molybdenum and niobium.

[0039] The vertical outer wall of the insulating cup 206 is provided with an annular groove, and the inner wall of the graphite tube 204 is provided with an annular protrusion which is mounted in cooperation with the annular groove of the outer wall of the insulating cup 206. Through the annular groove and the annular protrusion, the insulating cup 206 and the graphite tube 204 form a T-shaped mounting structure.

[0040] Principle and use process of the present invention:

[0041] The conductive bowl-shaped steel ring 302 of the upper end plug 3 and the lower end plug 4 are symmetrically arranged with the conductive doctor's hat steel ring 301 arranged below them, the conductive bowl-shaped steel ring 302 is provided with a phyllite sheet 303 inside, the conductive doctor's hat steel ring 301 is provided with a ceramic sheet 306 inside, the conductive doctor's hat steel ring 301 is provided with a phyllite ring 304 outside and a dolomite ring 305 arranged below it, this structure improves the conductive efficiency, enhances the sealing and pressure transmission effect of the upper and lower ends, the lower end of the ceramic sheet 306 is provided with a second heating sheet 203, the lower end of the second heating sheet 203 is provided with a first heating sheet 202, which can improve the pressure transmission and heat preservation effects, the inside of the phyllite layer 502 is provided with a sealing layer 501, the inside of the sealing layer 501 is provided with a magnesium oxide tube 207, which can reduce the cooling speed, the inside of the magnesium oxide tube 207 is provided with a graphite tube 204, and the inside of the graphite tube 204 is provided with an insulating cup 206, An indirect heating system is provided to improve the uniformity of the temperature field. The T-shaped stepped structure of the graphite tube 204 and the insulating cup 206 ensures the in-situ structure of the assembly system and improves the uniformity of the pressure field. A ceramic tube 205 is arranged inside the insulating cup 206, and a graphite heating cup 201 is arranged inside the ceramic tube 205. The graphite heating cup 201 and the first heating plate 202 form a first heating system to enhance the uniformity of the cavity temperature field. A metal cup 102 is arranged inside the graphite heating cup 201, and a polycrystalline powder core column 101 composed of diamond or cubic boron nitride is arranged inside the metal cup 102. A cup bottom is arranged at the bottom of the insulating cup 206, and a cup wall is arranged on the inner side of the insulating cup 206. A cup bottom is arranged at the bottom of the graphite heating cup 201, and a cup wall is arranged on the inner side of the graphite heating cup 201. A cup bottom is arranged at the bottom of the metal cup 102, and a cup wall is arranged on the inner side of the metal cup 102. The insulating cup 206, the graphite heating cup 201 and the metal cup 102 can increase the sealing of the cavity and the pressure transmission in the cavity, provide a uniform pressure field and temperature field, and improve the PCBN / PCD product quality and process stability. The metal cup 102 can completely wrap and seal the cubic boron nitride or diamond initial raw material core column to prevent gas and impurities from penetrating and entering, thereby ensuring the purity of the initial raw materials and reducing the risk of gas cannon in the high-pressure cavity due to the violent reaction of high pressure and high temperature in the cavity, thereby improving product quality and synthesis safety factor and improving work efficiency.

[0042] The present invention improves the conductive efficiency by assembling and matching the conductive bowl-shaped steel ring and the conductive doctor's cap steel ring in the end plug, and overcomes the disadvantage of pressure loss caused by inserting a large number of graphite sheets in the existing synthesis cavity. The structure with the conductive bowl-shaped steel ring outside and the conductive doctor's cap steel ring inside provides a stable sealing environment, and is therefore more suitable for the synthesis of PCBN / PCD materials.

[0043] The present invention forms a dual heating system by using the first and second heating plates, the graphite tube and the graphite heating cup, which can overcome the disadvantage of the existing synthesis cavity that the current directly passes through the polycrystalline powder core column for heating, which has an adverse effect on the synthesis quality of PCBN / PCD. It can solve the problem that in the heating process of the ordinary synthesis cavity, the temperature in the center of the cavity is high and the temperature at both ends is low, resulting in uneven overall heating and reduced product quality, thereby improving the production quality of PCBN / PCD.

[0044] The present invention can increase the sealing performance of the cavity and the pressure transmission in the cavity through the magnesium oxide tube and the ceramic tube, provide a uniform pressure field and temperature field, and improve the PCBN / PCD product quality and process stability.

[0045] The present invention can completely wrap and seal the cubic boron nitride or diamond initial raw material core column through the metal cup to prevent impurities from entering, ensure the purity of the initial raw material, reduce the risk of gas cannon in the high-pressure cavity that may occur due to the high-pressure and high-temperature violent reaction in the cavity, and improve product quality and synthesis safety factor.

[0046] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An assembled cavity structure of a synthetic PCBN-PCD material, comprising a core (1), a heating system (2), an upper end plug (3), a lower end plug (4) and a jacket (5), characterized in that: The outer sleeve (5) is a cylindrical structure with two ends open, the core (1) is located at the center of the axis of the outer sleeve (5), the outer portion of the core (1) wraps around the heating system (2), and the two ends of the outer sleeve (5) are respectively sealed with an upper end plug (3) and a lower end plug (4), the inner ends of the upper end plug (3) and the lower end plug (4) are respectively in extrusion contact with the heating system (2) at corresponding positions, and the vertical outer side wall of the heating system (2) is in contact with the inner wall of the outer sleeve (5); The heating system (2) comprises a first heating system and a second heating system, the first heating system comprising a graphite heating cup (201) and a first heating plate (202), the graphite heating cup (201) being wrapped around the outside of the core (1), the first heating plate (202) being fixedly arranged at the upper and lower ends of the graphite heating cup (201), the second heating system comprising a second heating plate (203) and a graphite tube (204), the graphite tube (204) being wrapped around the outside of the first heating system, and the two ends of the graphite tube (204) being respectively sealed. A second heating plate (203) is disposed, and the surfaces of the first heating plate (202) and the second heating plate (203) at the same end are in contact with each other; the upper end plug (3) and the lower end plug (4) both include a conductor that is in contact with the heating system (2); a ceramic tube (205) and an insulating cup (206) are coaxially disposed between the vertical walls of the graphite heating cup (201) and the graphite tube (204); the ceramic tube (205) and the outer wall of the graphite heating cup (201) are coaxially disposed in contact with each other; and the insulating cup (206) and the graphite tube (204) are coaxially disposed in contact with each other. The inner wall of the graphite tube (204) is coaxially fitted, the outer wall of the graphite tube (204) is coaxially fitted with a magnesium oxide tube (207), the upper end plug (3) comprises a conductive doctor hat steel ring (301) and a conductive bowl-shaped steel ring (302), the vertical side wall end of the conductive bowl-shaped steel ring (302) is in contact with and conductive to the plane part of the conductive doctor hat steel ring (301), the conductive bowl-shaped steel ring (302) is filled with pyrophyllite sheets (303), the vertical sleeve of the conductive doctor hat steel ring (301) is filled with ceramic sheets (306), and the conductive doctor hat A dolomite ring (305) and a pyrophyllite ring (304) are coaxially fixedly arranged on the outside of the vertical sleeve of the steel ring (301) in sequence from the end to the bottom, the lower end plug (4) and the upper end plug (3) have the same structure, the pyrophyllite rings (304) of the lower end plug (4) and the upper end plug (3) are respectively pressed and contacted with the second heating plate (203) at the corresponding position, and the vertical sleeve ends of the conductive doctoral hat steel ring (301) inside the lower end plug (4) and the upper end plug (3) are in contact with the second heating plate (203) at the corresponding position and are conductive.

2. The assembled cavity structure of the synthetic PCBN-PCD material according to claim 1, characterized in that: The outer casing (5) comprises, from the inside to the outside, a sealing layer (501) and a pyrophyllite layer (502) which are coaxially arranged and bonded together, and the inner wall of the sealing layer (501) is in compression contact with the vertical outer wall of the heating system (2).

3. The assembled cavity structure of the synthetic PCBN-PCD material according to claim 1, characterized in that: The core body (1) comprises two groups of metal cups (102) with openings on one side and the openings facing each other, and a powder core column (101) is filled in a closed space surrounded by the two groups of metal cups (102).

4. The assembled cavity structure of the synthetic PCBN-PCD material according to claim 1, characterized in that: The graphite heating cup (201) is composed of two groups of graphite cups with openings on one side and the openings are opposite to each other. The insulating cup (206) is composed of two groups of insulating cup bodies with openings on one side and the openings are opposite to each other. A through hole is provided at the bottom of the insulating cup body, and the first heating plate (202) is fixedly arranged in the through hole.

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