A process for synthesizing surface corrugated diamonds

Abstract

The present application belongs to the technical field of synthetic diamond production and processing, and proposes a process for synthesizing diamond with a wavy surface. A -300 mesh fine powder catalyst is prepared, containing 19% Ni, 0.05% Ti, 0.85% Si3N4, 0.1% CeO2, and 80% Fe. The -300 mesh fine spherical graphite powder is mixed with the premixed powder catalyst in a three-dimensional mixer and granulated, and then pressed into a core column. The core column is placed in a vacuum furnace for treatment and then loaded into a synthetic block for heating. A six-surface press is then used for high-temperature and high-pressure synthesis. The present application changes the raw material of the prepared high-iron catalyst, which not only speeds up the growth of diamond but also produces a noticeable wavy effect on the surface. By changing the structure of the synthetic block to increase the axial pressure, and by matching specific pressure and power to adjust the process, diamond with a wavy surface can be synthesized without affecting the overall performance of the diamond, which can solve the problem of low holding force of diamond during use.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of synthetic diamond production and processing, and particularly relates to a synthetic diamond process with a surface wave pattern. BACKGROUND

[0002] Diamond has excellent mechanical, electrical, thermal and chemical properties, and is widely used in petroleum drilling, stone processing, mechanical processing, electronic industry, aerospace, biosensor, semiconductor and quantum device, etc. fields, and is particularly introduced into the grinding industry as super abrasive to significantly improve the processing efficiency and processing quality of parts, and also prolongs the life of the grinding wheel and improves the dimensional stability of the processed parts.

[0003] At present, in the diamond tool grinding process, because the diamond surface is relatively smooth and not rough enough, the bonding between the diamond and the binder is not firm, and during the grinding process, the whole diamond particle often falls off, which greatly shortens the service life. In view of this problem, there is still a lack of effective solution, and at present, the surface coating or surface etching technology is mainly used to change the properties of the diamond surface to make the diamond surface rough, which in some way solves the problem of low holding force, but because the cost is relatively high and the technical difficulty is relatively large, it limits the mass production of enterprises on this product. SUMMARY

[0004] The present application is directed to the technical problems of the above-mentioned diamond, and provides a synthetic diamond process with a surface wave pattern, which is reasonable in design, does not affect the overall performance of the diamond, increases the roughness of the diamond surface, and solves the problem of low holding force of the diamond during use.

[0005] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is that the present application provides a synthetic diamond process with a surface wave pattern, which comprises the following steps:

[0006] S1, preparing -300 fine powder catalyst for standby, the raw material of the powder catalyst is as follows in terms of weight percentage: Ni: 19%, Fe: 80%;

[0007] S2, mixing a small amount of Ti, Si3N4 and rare earth oxides with the prepared powder catalyst for 3h standby;

[0008] S3, selecting -300 mesh fine spherical graphite powder; mixing the pre-mixed catalyst and graphite powder in a three-dimensional mixer at a mass ratio of 10:3-6 for 3-5h, and then putting them into a granulator for twice granulation standby;

[0009] S4, loading the granulated mixture into a mold, and pressing it into a core column using a four-column press, the core column size is Φ57mmx48mm, and the core column density is 3.2-3.4g / cm 3 ;

[0010] S5, the pressed core column is placed in a vacuum furnace, vacuum treatment is carried out at 1080 DEG C for 8-10h, hydrogen reduction is used to remove impurities, and then natural cooling is carried out to room temperature under nitrogen protection, and vacuum packaging is carried out after furnace discharge;

[0011] S6, the core column is placed in the assembled block, the assembled block is placed in a high-temperature oven and heated at 135 DEG C for 8h, and then the high-temperature high-pressure sintering of the block is carried out in a cubic press, the sintering temperature is 1280-1360 DEG C, the heating time is 3000s, and the internal pressure of the sintering cavity is 5.4-5.6 Gpa;

[0012] The pressure of the cubic press is adjusted, the pressure of the cubic press is uniformly increased to 48 Mpa at a speed of 0.6 Mpa / s of the hydraulic system, then heating is started, and then the pressure is increased to 58 Mpa at a speed of 0.35 Mpa / s, pressure maintaining is carried out for 580s-620s, then the pressure is increased to 68 Mpa within 20s, pressure maintaining is carried out for 120s, the pressure is rapidly increased to 70.5 Mpa within 1s, pressure maintaining is carried out for 300s, the pressure is rapidly increased to 74 Mpa within 1s, pressure maintaining is carried out for 300s, the pressure is rapidly increased to 78 Mpa within 1s, pressure maintaining is carried out for 300s, the pressure is rapidly increased to 83 Mpa within 2s, pressure maintaining is carried out for 300s, the pressure is rapidly increased to 88.5 Mpa within 2s again, a pressure maintaining stage is entered, pressure maintaining is carried out for 150s-180s, and then hot pressure relief is carried out, the pressure is reduced to 72 Mpa at a speed of 0.2 Mpa / s, the pressure is reduced to 30 Mpa at a speed of 0.55 Mpa / s, and rapid pressure relief is completed;

[0013] The power of the cubic press is adjusted, the initial power of the cubic press is 9.6-9.8 kw, the initial power is maintained for 620s-660s, the power is first reduced, the power is reduced to 8.6-8.8 kw within 20s, and the power is maintained for 150s-180s, then the power is increased to 8.7 kw within 30s, and the power is maintained for 200s, then the power is increased to 8.8 kw, and the power is maintained for 480s, then the power is reduced to 8.35 kw, and then the power is uniformly reduced to 8.15 kw, and the power is uniformly reduced to 0 within 30s;

[0014] S7, the synthesized graphite rod is subjected to physical and chemical treatment, and then the diamond with corrugated crystal faces is obtained.

[0015] As preferred, in step S2, the rare earth oxide is CeO2, and the Ti, Si3N4 and CeO2 are 0.05%, 0.85% and 0.1% by weight percentage.

[0016] As preferred, in step S3, the purity of the graphite reaches an impurity content of 30 PPM or less.

[0017] Preferably, in step S6, the synthetic block comprises metal tubes, magnesium oxide tubes, metal heating tubes and talc sleeves distributed from inside to outside, two ends of the metal tubes are provided with first metal sheets, two ends of the magnesium oxide tubes are provided with magnesium oxide sheets, two ends of the metal heating tubes are provided with graphite heating sheets, opposite sides of the graphite heating sheets at two ends are provided with second metal sheets, and two ends of the talc sleeves are provided with plugs.

[0018] Preferably, the step of assembling the synthetic block and the core column is as follows: the core column is placed into a metal tube with a wall thickness of 0.3 mm, two ends of the metal tube are provided with first metal sheets with a thickness of 0.5 mm, the outside of the metal tube is provided with a magnesium oxide tube, two ends of the magnesium oxide tube are provided with magnesium oxide sheets with a thickness of 2 mm, the outside of the magnesium oxide tube is provided with a metal heating tube, two ends of the metal heating tube are provided with graphite heating sheets, and the outside of the metal heating tube is provided with talc, two ends of the talc are provided with plugs, and one second metal sheet with a thickness of 0.3 mm is arranged on the opposite side of each plug.

[0019] Preferably, in step S7, the step of physical and chemical treatment is as follows: after the synthetic graphite rod is broken, the graphite rod is soaked in mixed acid for 1-2 h to remove the graphite, then the graphite rod is placed into a beaker containing aqua regia and heated for 20-30 min to remove the catalyst, and then the graphite rod is boiled in water and fried to obtain diamond with corrugated crystal surface.

[0020] Compared with the prior art, the application has the following advantages and positive effects:

[0021] 1. The process for synthesizing diamond with corrugated surface provided by the application changes the raw material of high-iron catalyst, uses high-iron catalyst to accelerate the growth of diamond, uses trace CeO2 to reduce the oxygen content in the raw material and increase the activation performance of the catalyst, uses trace Ti and Si3N4 to change the crystal lattice of the crystal surface and make the diamond surface have obvious corrugated effect, changes the structure of the synthetic block to increase the axial pressure, and then matches specific pressure and power to adjust the process, so that the shear force generated by the movement of the earth's crust in the earth's interior can be simulated, the diamond can be in a state of relative pressure and temperature mismatch, the diamond with corrugated surface can be synthesized without affecting the overall performance of the diamond, the roughness of the diamond surface is increased, and the problem of low holding force of the diamond in use is solved. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0023] Figure 1A graph of a diamond process for synthesizing surface ripples provided for an embodiment;

[0024] Figure 2 An enlarged schematic view of a product synthesized for a diamond process for synthesizing surface ripples. DETAILED DESCRIPTION

[0025] In order to enable a more complete understanding of the above-mentioned objects, features and advantages of the present application, the following describes the present application in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0026] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and therefore, the present application is not limited to the specific embodiments disclosed in the following description.

[0027] Embodiments, as shown in Figure 1 and Figure 2 The present application provides a diamond process for synthesizing surface ripples, comprising the following steps:

[0028] S1, preparing -300 fine powder catalyst, the raw material of the powder catalyst is as follows in terms of percentage by weight: Ni: 19%, Fe: 80%;

[0029] S2, mixing a small amount of Ti, Si3N4 and rare earth oxides with the prepared powder catalyst for 3 hours in advance for standby;

[0030] S3, selecting -300 mesh fine spherical graphite powder; mixing the pre-mixed catalyst and graphite powder in a mass ratio of 10:3-6 in a three-dimensional mixer for 3-5 hours, and then putting them into a granulator for twice granulation for standby;

[0031] S4, loading the granulated mixture into a mold, and pressing it into a core column using a four-column press, the core column size is Φ57mmx48mm, and the core column density is 3.2-3.4g / cm 3 ;

[0032] S5, placing the pressed core column into a vacuum furnace, vacuum treating it at 1080℃ for 8-10 hours, reducing and removing impurities with hydrogen, and then naturally cooling it to room temperature under nitrogen protection, and vacuum packaging after taking it out of the furnace;

[0033] S6, assemble the synthesis block and put the core column into the synthesis block, put the assembled synthesis block into a high temperature oven at 135℃ for 8h, and then put it into a six-surface pressing machine for high temperature and high pressure synthesis, the six-surface pressing machine has a cylinder diameter of Φ850, the top hammer surface is 70*70mm, the hammer surface angle is 42 degrees, the HT-V electric control, the synthesis temperature is 1280-1360℃, the heating time is 3000s, and the internal pressure of the synthesis cavity is 5.4-5.6Gpa;

[0034] Adjust the pressure of the six-surface pressing machine, and the pressure of the six-surface pressing machine is uniformly over-pressured to 48Mpa at a speed of 0.6mpa / s of the hydraulic system, then heated, and then increased to 58mpa at a speed of 0.35mpa / s, and kept for 580s-620s; then the pressure is increased to 68Mpa within 20s, and kept for 120s; rapidly over-pressured to 70.5Mpa within 1s, and kept for 300s; rapidly over-pressured to 74Mpa within 1s, and kept for 300s; rapidly over-pressured to 78Mpa within 1s, and kept for 300s; rapidly over-pressured to 83Mpa within 2s, and kept for 300s; again rapidly over-pressured to 88.5Mpa within 2s; enter the pressure keeping stage, and keep for 150s-180s, then discharge with heat, discharge to 72Mpa at a speed of 0.2mpa / s, discharge to 30Mpa at a speed of 0.55mpa / s, and complete the rapid discharge;

[0035] Adjust the power of the six-surface pressing machine, the initial power of the six-surface pressing machine is 9.6kw-9.8kw, and the initial power is kept for 620s-660s; the first power is reduced, and the power is reduced to 8.6kw-8.8kw within 20s, and kept for 150s-180s; then the power is increased to 8.7kw within 30s, and kept for 200s; then the power is increased to 8.8kw, and kept for 480s; then the power is reduced to 8.35kw, and then uniformly reduced to 8.15kw; the power is uniformly reduced to 0 within 30s;

[0036] S7, after the synthesized graphite rod is subjected to physical and chemical treatment, the crystal surface of the diamond has a corrugated shape.

[0037] In the process of the present application, on one hand, the raw material of the high-iron catalyst is changed, and on the other hand, the synthesis block is used to assist the synthesis. Specifically, the high-iron catalyst can accelerate the growth speed of the diamond, the trace CeO2 can reduce the oxygen content in the raw material, increase the activation performance of the catalyst, and the trace Ti and Si3N4 can make the crystal surface have lattice wrinkle changes, so that the diamond surface has obvious wave effect; by changing the structure of the synthesis block to increase the axial pressure effect, and matching the specific pressure and power adjustment process in step S6, the shear force generated by the earth crust movement in the earth interior can be simulated, the diamond can be in a state of relative pressure and temperature mismatch, so that the diamond with surface wave is synthesized without affecting the overall performance of the diamond, the roughness of the diamond surface is increased, and the holding force of the diamond in the use process is well solved.

[0038] In step S2, the rare earth oxide is CeO2, and the Ti, Si3N4 and CeO2 are 0.05%, 0.85% and 0.1% by weight percentage.

[0039] In order to improve the quality of the synthesized product in the process of the present application, in step S3, the purity of the graphite is 30 PPM or less, by adding the proportion of the components into the high-iron catalyst, the physical performance of the wave is not excessively large while the catalyst spark is ensured, so as to ensure the yield of the final synthesized product and the application performance in the mechanical processing field

[0040] In order to improve the efficiency of forming the wave structure on the surface of the diamond, in step S6, the synthesis block comprises metal pipes, magnesium oxide pipes, metal heating pipes and phylite sleeves distributed from inside to outside, both ends of the metal pipe are provided with first metal sheets, both ends of the magnesium oxide pipe are provided with magnesium oxide sheets, both ends of the metal heating pipe are provided with graphite heating sheets, the opposite sides of the graphite heating sheets at both ends are provided with second metal sheets, and both ends of the phylite sleeve are provided with plugs.

[0041] More specifically, the assembly step of the synthesis block and the core column is that the core column is placed in the metal pipe with a wall thickness of 0.3 mm, both ends are the first metal sheets with a thickness of 0.5 mm, the outside is inlaid with the magnesium oxide pipe, both ends are overlapped with the magnesium oxide sheets with a thickness of 2 mm, the outer layer is inlaid with the metal heating pipe, both ends are overlapped with the graphite heating sheets, the outermost layer is the phylite, both ends of the phylite are the plugs, and one piece of the second metal sheet with a thickness of 0.3 mm is added on the opposite side of the plug.

[0042] The present application improves the synthetic block, uses high-density pressing for the core column, changes the traditional iron cup of the core column into a metal tube, thickens the metal sheet at both ends, changes the dolomite cup into a magnesium oxide tube, thickens the magnesium oxide sheet at both ends, adds a metal sheet at both ends of the plug, increases the axial pressure gradient by improving the synthetic block, and gradually increases the range of pressure compensation through process dynamic pressure compensation, simulates the dynamic shear force generated by the movement of the earth's crust plate, and can make the diamond be in a state of relative pressure and temperature mismatch. In this state, trace elements in the catalyst can also act in this specific area, thereby playing a key role in the diamond crystal surface ripple.

[0043] In order to facilitate the extraction of synthetic products, in step S7, the physical and chemical treatment step is to soak the broken graphite rod with mixed acid for 1-2h, remove the graphite, then put it into a beaker containing aqua regia and heat for 20-30min to remove the catalyst, then boil water, dry and get the diamond with wavy crystal surface.

[0044] The above is only a preferred embodiment of the present application, and is not intended to limit the other forms of the present application. Any skilled person in the art can use the disclosed technical content to make changes or modifications to equivalent embodiments applied to other fields. However, any simple modification, equivalent change and modification of the above embodiments without departing from the technical solution content of the present application, and in accordance with the technical essence of the present application, still belongs to the protection scope of the technical solution of the present application.

Claims

1. A process for synthesizing surface corrugated diamond characterized in that, It comprises the following steps: S1, preparing -300 fine powder catalyst, the raw material of the powder catalyst is 19% of Ni, 80% of Fe by weight percentage; S2, a small amount of Ti, Si3N4 and rare earth oxides are pre-mixed with the prepared powder catalyst for 3 hours for standby; S3, select -300 mesh spherical graphite powder; the pre-mixed catalyst and graphite powder are mixed in a three-dimensional mixer at a mass ratio of 10: (3-6) for 3-5 hours, and then put into a granulator for twice granulation standby; S4, the granulated mixture is loaded into a mold, and a core column is pressed by a four-column press, the core column has a size of Φ57mmx48mm, and the core column density is 3.2-3.4g / cm 3 ; S5, the prepared core column is placed in a vacuum furnace, treated at 1080℃ for 8-10h, reduced by hydrogen to remove impurities, and then naturally cooled to room temperature under nitrogen protection, and vacuum packaged after taking out of the furnace; S6, assemble the synthesis block and put the core column into the synthesis block, put the assembled synthesis block into a high temperature oven and heat at 135℃ for 8h, then put it into a six-surface pressing machine for high temperature and high pressure synthesis, the synthesis temperature is 1280-1360℃, the heating time is 3000s, and the internal pressure of the synthesis cavity is 5.4-5.6GPa; the synthesis block comprises a metal pipe, a magnesium oxide pipe, a metal heating pipe and a talc sleeve distributed from inside to outside, the two ends of the metal pipe are provided with first metal sheets, the two ends of the magnesium oxide pipe are provided with magnesium oxide sheets, the two ends of the metal heating pipe are provided with graphite heating sheets, and the opposite sides of the graphite heating sheets at the two ends are provided with second metal sheets, and the two ends of the talc sleeve are provided with plugs; Adjust the pressure of the six-surface pressing machine, and start heating after the pressure of the six-surface pressing machine is uniformly over-pressured to 48MPa at a speed of 0.6MPa / s of the hydraulic system, then increase to 58MPa at a speed of 0.35MPa / s, and keep pressure for 580s-620s; then increase the pressure to 68MPa within 20s, keep pressure for 120s; rapidly over-press to 70.5MPa within 1s, keep pressure for 300s; rapidly over-press to 74MPa within 1s, keep pressure for 300s; rapidly over-press to 78MPa within 1s, keep pressure for 300s; rapidly over-press to 83MPa within 2s, keep pressure for 300s; again rapidly over-press to 88.5MPa within 2s; enter the pressure keeping stage, keep pressure for 150s-180s, then discharge with heat, discharge to 72MPa at a speed of 0.2MPa / s, discharge to 30MPa at a speed of 0.55MPa / s, and complete the rapid discharge; Adjust the power of the six-surface pressing machine, the initial power of the six-surface pressing machine is 9.6kw-9.8kw, the initial power is kept for 620s-660s; the power is first lowered, the power is lowered to 8.6kw-8.8kw within 20s, and kept for 150s-180s; then the power is increased to 8.7kw within 30s, and kept for 200s; then the power is increased to 8.8kw, and kept for 480s; then the power is decreased to 8.35kw, and then uniformly decreased to 8.15kw; the power is uniformly decreased to 0 within 30s; S7, after the synthesized graphite rod is subjected to physical and chemical treatment, the crystal surface of the diamond is corrugated.

2. A process for synthesizing a faceted surface of a diamond according to claim 1, wherein, In step S2, the rare earth oxide is CeO2, and the Ti, Si3N4, CeO2 are 0.05%, 0.85%, 0.1% by weight percentage.

3. A process for synthesizing faceted surface ripples of diamond as claimed in claim 1, wherein, In step S3, the purity of the graphite reaches 30 PPM or less of impurity content.

4. A process for synthesizing faceted surface ripples of diamond as claimed in claim 1, wherein, The assembling step of the synthetic block and the stem is that the stem is placed into a metal tube with a wall thickness of 0.3 mm, the two ends are first metal sheets with a thickness of 0.5 mm, the outside is a magnesium oxide tube inlay, the two ends are magnesium oxide sheets with a thickness of 2 mm, the outer layer is a metal heating tube inlay, the two ends are graphite heating sheets, and the outermost layer is talc, the two ends of the talc are plugs, and one piece of second metal sheet with a thickness of 0.3 mm is added on the opposite side of the plug.

5. A process for synthesizing surface corrugated diamonds as claimed in claim 1 wherein, In step S7, the physicochemical treatment step is that the synthesized graphite rod is crushed, soaked in mixed acid for 1-2 h, the graphite is removed, then placed into a beaker containing aqua regia and heated for 20-30 min to remove the catalyst, then boiled water, and fried dry to obtain diamond with corrugated crystal surface.

Images