Alloy for synthesizing IIa type diamond and preparation method and application thereof

Abstract

The invention discloses an alloy for synthesizing IIa type diamonds, which is prepared from the following raw materials in percentage by mass: 70-85% of iron powder, 15-25% of aluminum powder and 2-3% of titanium powder, and a preparation method of the alloy comprises the following steps: respectively weighing the iron powder, the aluminum powder and the titanium powder according to the mass percent; after iron powder, aluminum powder and titanium powder are evenly mixed, the mixture is put into a vacuum smelting furnace to be smelted, and an intermediate material is obtained after smelting; pressing the material into an alloy bar by using a hot extrusion die; carrying out linear cutting processing on the alloy bar to obtain an initial alloy sheet; and the initial alloy sheet is subjected to vacuum sintering purification, the alloy for synthesizing the IIa type diamond is obtained, and the alloy is applied to synthesis of the IIa type diamond. The quality of the IIa type diamond prepared by the method is guaranteed, the yield is high, and the high-yield and high-quality IIa type diamond can be synthesized under the condition of low cost.

Description

Technical Field

[0001] The invention belongs to the technical field of artificially synthesized colorless diamonds, relates to an alloy for synthesizing type IIa diamonds, and also relates to a preparation method and application of the alloy. Background Art

[0002] As one of the emerging choices in the field of diamond consumption, artificial diamond is mainly used to make diamond jewelry and other fashionable consumer goods. It has obvious competitive advantages in terms of quality, price, environmental protection and technology. With the continuous improvement of artificial diamond synthesis technology and the change of market consumption concepts and consumption habits, the market attention and market demand for artificial diamonds have increased significantly, and it has become one of the most important development directions of the artificial diamond industry. For example, the patent with application number CN107268078B proposes a method for artificial synthesis of gem-grade colorless diamonds. The colorless diamonds synthesized by the method described in the present invention can completely replace natural diamonds and have strong market advantages. However, the method adopts a static pressure molten powder synthesis method. Since the synthesis method has problems such as difficult control of the growth environment and growth rate, high production cost, fine particle size and relatively poor color and clarity, it is not suitable for the synthesis of large-sized colorless diamonds.

[0003] The breakthrough in synthetic diamond synthesis technology has only been achieved recently, and the synthetic diamond industry is in its early stages of development. Market consumption demand and production supply levels are growing rapidly, and there is a certain gap between supply capacity and consumption demand. In the face of fierce competition, it is necessary to develop a new synthesis technology for alloy materials used to synthesize diamonds, further improve and enhance the synthesis quality of alloy materials, reduce production costs, and improve economic and social benefits. Synthesizing a stable alloy material structure is still the direction for the industry to work together to achieve technological breakthroughs. Summary of the invention

[0004] The purpose of the present invention is to provide an alloy for synthesizing type IIa diamond, which solves the problems of high production cost of alloy materials and insufficient structural stability in the prior art.

[0005] Another object of the present invention is to provide a preparation method and application of the above alloy.

[0006] The technical solution adopted by the present invention is that the alloy used for synthesizing type IIa diamond is prepared from iron powder, aluminum powder and titanium powder as raw materials, the mass percentage of iron powder is 70%-85%, the mass percentage of aluminum powder is 15%-25%, and the mass percentage of titanium powder is 2-3%.

[0007] The present invention is also characterized in that:

[0008] The iron powder, aluminum powder and titanium powder are all single substance powders, and the particle sizes of the iron powder, aluminum powder and titanium powder are all not greater than 300 meshes.

[0009] Another technical solution of the present invention is characterized in that a method for preparing an alloy for synthesizing type IIa diamond comprises the following steps:

[0010] Step 1: Weigh the following components according to mass percentage: 70%-85% iron powder, 15%-25% aluminum powder, and 2-3% titanium powder;

[0011] Step 2: After the iron powder, aluminum powder and titanium powder are evenly mixed, they are placed in a vacuum melting furnace for melting to obtain an intermediate material;

[0012] Step 3: Press the intermediate material into an alloy rod using a hot extrusion die;

[0013] Step 4: Perform wire cutting on the alloy rod to obtain an initial alloy sheet with a thickness of 5-20 mm;

[0014] Step 5: Place the initial alloy sheet into a vacuum furnace, evacuate the vacuum furnace, introduce hydrogen after the vacuum degree reaches 0.1Pa-20Pa, and perform vacuum sintering and purification when the vacuum degree is 0.03-0.05MPa to obtain an alloy for synthesizing type IIa diamond.

[0015] The smelting time is specifically 2-10 hours and the smelting temperature is 1000-2000°C.

[0016] The diameter of the alloy rod is 35-70mm.

[0017] The vacuum sintering purification is specifically as follows: the vacuum furnace is heated from room temperature to 700-800°C within a time period of 0.5-2h, then kept warm for 1-15h, and then heated to 900-1000°C within a time period of 0.5-2h, and then kept warm for 1-15h, and finally heated to 1000-1100°C within a time period of 0.5-2h, and kept warm for 1-15h.

[0018] Application of alloys for synthesizing type IIa diamond in synthesizing type IIa diamond.

[0019] The beneficial effects of the present invention are:

[0020] 1. The alloy for synthesizing type IIa diamond of the present invention is based on the temperature gradient method, and an alloy material for synthesizing type IIa diamond is proposed. Compared with the traditional FeNi-based alloy catalyst, the alloy material has a lower cost. In addition, the alloy material uses Fe and Al as the main formula raw materials, and the added aluminum element has a denitrification performance. Compared with the prior art that requires additional addition of aluminum foil, copper foil and other thin sheets for denitrification, the assembly method of the present invention is simpler, and its fault tolerance rate is significantly improved.

[0021] 2. The alloy for synthesizing type IIa diamond of the present invention is beneficial to nitrogen removal by adding Fe and Al. On the other hand, the alloy promotes and complements each other among the elements, takes both functions and uses into consideration, reduces the amount of inter-crystallization and spontaneous nucleation, refines the grains, purifies the alloy sheets, and improves the catalytic activity, further ensuring the product quality of type IIa diamond and providing convenient conditions for the uniformity and stability of the growth process.

[0022] Since the main function of the growth process is the denitrification performance, combined with the current existing technology, basically based on the temperature gradient method, the synthesis chamber is composed of a carbon source layer, an iron-nickel or iron-cobalt catalyst layer, a denitrification layer and a growth layer. On the one hand, the selection of the catalyst main base, based on the iron base, uses aluminum as the main formula raw material, which is lower in cost. While removing nitrogen, the grains are refined to improve the corresponding activity. On the other hand, the current use of sheet-shaped denitrification layers with polycrystalline and spontaneous nuclei is more common, especially the denitrification elements are concentrated on a certain radial section, and the denitrification efficiency is affected by the longitudinal distance and the amount of denitrification. The denitrification agent distribution in the entire synthesis chamber is extremely uneven, which is particularly prone to cause instability in the growth environment and process, especially clarity and color. By adding denitrification elements to the catalyst, taking into account the catalyst efficiency, designing a suitable proportion formula and molding process, the growth process and denitrification and impurity removal capabilities are uniform and stable during the synthesis of type IIa diamonds.

[0023] 3. The alloy for synthesizing type IIa diamond of the present invention has the characteristics of uniform composition, regular organizational structure, smooth surface, lower impurity content, especially lower nitrogen and oxygen content, and fine particle size distribution. The alloy is more conducive to synthesizing type IIa diamond.

[0024] In summary, the alloy for synthesizing type IIa diamonds of the present invention, the preparation method and application thereof, are simple to operate, the structure of the synthetic alloy material is stable, the synthesis effect is good, the nitrogen removal efficiency is high, the product quality of type IIa diamonds is guaranteed, and the yield is high. The present invention can synthesize high-yield and high-quality type IIa diamonds under low-cost conditions, and can be widely promoted and applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of type IIa diamond according to example 1 of the alloy application of the present invention for synthesizing type IIa diamond. DETAILED DESCRIPTION

[0026] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] The alloy used for synthesizing type IIa diamond is prepared from iron powder, aluminum powder and titanium powder as raw materials, the mass percentage of iron powder is 70%-85%, the mass percentage of aluminum powder is 15%-25%, and the mass percentage of titanium powder is 2-3%, wherein the iron powder, aluminum powder and titanium powder are all single substance powders, and the particle sizes of the iron powder, aluminum powder and titanium powder are not greater than 300 meshes.

[0028] A method for preparing an alloy for synthesizing type IIa diamond, characterized in that it comprises the following steps:

[0029] Step 1: Weigh the following components according to mass percentage: 70%-85% iron powder, 15%-25% aluminum powder, and 2-3% titanium powder;

[0030] Step 2: After the iron powder, aluminum powder and titanium powder are evenly mixed, they are placed in a vacuum melting furnace for melting to obtain an intermediate material, wherein the melting time is 2-10 hours and the melting temperature is 1000-2000°C. ;

[0031] Step 3: Press the intermediate material into an alloy rod using a hot extrusion die, the diameter of the alloy rod is 35-70 mm;

[0032] Step 4: Perform wire cutting on the alloy rod to obtain an initial alloy sheet with a thickness of 5-20 mm;

[0033] Step 5: Place the initial alloy sheet into a vacuum furnace, evacuate the vacuum furnace, introduce hydrogen after the vacuum degree reaches 0.1Pa-20Pa, and perform vacuum sintering and purification when the vacuum degree is 0.03-0.05MPa to obtain an alloy for synthesizing type IIa diamond.

[0034] The vacuum sintering purification is specifically as follows: the vacuum furnace is heated from room temperature to 700-800°C within a time period of 0.5-2h, then kept warm for 1-15h, and then heated to 900-1000°C within a time period of 0.5-2h, and then kept warm for 1-15h, and finally heated to 1000-1100°C within a time period of 0.5-2h, and kept warm for 1-15h.

[0035] Example 1

[0036] Weigh 825 grams of 300-mesh iron powder, 150 grams of 300-mesh aluminum powder, and 25 grams of 300-mesh titanium powder, mix the iron powder, aluminum powder, and titanium powder evenly, and then put them into a vacuum melting furnace for melting, wherein the melting time is 3 hours, the melting temperature is 1550° C., and the material is obtained after the melting is completed; the material is pressed into an alloy rod with a hot extrusion die, and the diameter of the alloy rod is 60 mm;

[0037] The alloy rod is wire-cut according to the technical parameter size to obtain an initial alloy sheet of 14 mm, and the initial alloy sheet is placed in a vacuum furnace, which is evacuated. Hydrogen is introduced after the vacuum degree reaches 1.5 Pa, and vacuum sintering and purification are carried out when the vacuum degree is 0.03 MPa. The vacuum sintering and purification are specifically carried out by heating the temperature to 700°C in 1 hour, keeping it warm for 2 hours, continuing to heat it to 950°C in 0.5 hours, keeping it warm for 8 hours, and finally heating it to 1050°C in 1 hour, keeping it warm for 10 hours, to obtain an alloy for synthesizing type IIa diamond.

[0038] The IIa type diamond in this example is Figure 1 As shown, its synthesis time is 120h, the yield is 78ct, and its particle size composition is shown in the following table:

[0039] granularity <1ct 1-2ct 2-3ct >3ct Proportion 3.2％ 74.4％ 19.4％ 3％

[0040] Chroma D / E color, clarity VS and above.

[0041] Example 2

[0042] Weigh 700 g of 400-mesh iron powder, 250 g of 400-mesh aluminum powder, and 50 g of 400-mesh titanium powder, mix the iron powder, aluminum powder, and titanium powder evenly, and then put them into a vacuum melting furnace for melting, wherein the melting time is 2 hours and the melting temperature is 1000° C. After the melting is completed, the material is obtained; the material is pressed into an alloy rod with a hot extrusion die, and the diameter of the alloy rod is 35 mm;

[0043] The alloy rod is wire-cut according to the technical parameter size to obtain an initial alloy sheet of 5 mm, and the initial alloy sheet is placed in a vacuum furnace, which is evacuated. Hydrogen is introduced after the vacuum degree reaches 0.1 Pa, and vacuum sintering and purification are carried out when the vacuum degree is 0.04 MPa. The vacuum sintering and purification are specifically carried out by heating the temperature to 750°C in 2 hours, keeping it warm for 1 hour, continuing to heat the temperature to 900°C in 1 hour, keeping it warm for 15 hours, and finally heating the temperature to 1000°C in 0.5 hours, and keeping it warm for 15 hours to obtain an alloy for synthesizing type IIa diamond.

[0044] The synthesis time of type IIa diamond in this example is 100 hours, the yield is 67 ct, and its particle size composition is shown in the following table:

[0045] granularity <1ct 1-2ct 2-3ct >3ct Proportion 5.2％ 75.9％ 16.6％ 2.3％

[0046] Chroma D / E color, clarity VS and above.

[0047] Example 3

[0048] Weigh 850 g of 300-mesh iron powder, 130 g of 500-mesh aluminum powder, and 20 g of 400-mesh titanium powder, mix the iron powder, aluminum powder, and titanium powder evenly, and then put them into a vacuum melting furnace for melting, wherein the melting time is 10 hours, the melting temperature is 2000° C., and the material is obtained after the melting is completed; the material is pressed into an alloy rod with a hot extrusion die, and the diameter of the alloy rod is 70 mm;

[0049] The alloy rod is wire-cut according to the technical parameter size to obtain an initial alloy sheet of 20 mm, and the initial alloy sheet is placed in a vacuum furnace, which is evacuated. Hydrogen is introduced after the vacuum degree reaches 20 Pa, and vacuum sintering and purification are carried out when the vacuum degree is 0.05 MPa. The vacuum sintering and purification are specifically carried out by heating the temperature to 800°C in 0.5 h, keeping the temperature for 15 h, continuing to heat the temperature to 1000°C in 2 h, keeping the temperature for 1 h, and finally heating the temperature to 1100°C in 2 h, keeping the temperature for 1 h, to obtain an alloy for synthesizing type IIa diamond.

[0050] The synthesis time of type IIa diamond in this example is 216 hours, the yield is 87 ct, and its particle size composition is shown in the following table:

[0051] granularity <2ct 2-3ct 3-4ct >4ct Proportion 2.1％ 76.3％ 16.2％ 5.4％

[0052] Chroma D / E color, clarity VS and above.

Claims

1. An alloy for synthesizing type IIa diamond, characterized in that: The invention is prepared from iron powder, aluminum powder and titanium powder as raw materials, wherein the mass percentage of the iron powder is 70%-85%, the mass percentage of the aluminum powder is 15%-25%, and the mass percentage of the titanium powder is 2-3%.

2. The alloy for synthesizing type IIa diamond according to claim 1, characterized in that: The iron powder, aluminum powder and titanium powder are all single substance powders, and the particle sizes of the iron powder, aluminum powder and titanium powder are all no greater than 300 meshes.

3. The method for preparing the alloy according to any one of claims 1 to 2, characterized in that: The following steps are involved: Step 1: Weigh the following components according to mass percentage: 70%-85% iron powder, 15%-25% aluminum powder, and 2-3% titanium powder; Step 2: After the iron powder, aluminum powder and titanium powder are evenly mixed, they are placed in a vacuum melting furnace for melting to obtain an intermediate material; Step 3: pressing the intermediate material into an alloy rod using a hot extrusion die; Step 4: performing wire cutting on the alloy rod to obtain an initial alloy sheet with a thickness of 5-20 mm; Step 5: Place the initial alloy sheet into a vacuum furnace, evacuate the vacuum furnace, introduce hydrogen after the vacuum degree reaches 0.1Pa-20Pa, and perform vacuum sintering and purification when the vacuum degree is 0.03-0.05MPa to obtain an alloy for synthesizing type IIa diamond.

4. The method for preparing the alloy according to claim 3, characterized in that: The smelting conditions are specifically as follows: the smelting time is 2-10 hours and the smelting temperature is 1000-2000°C.

5. The method for preparing the alloy according to claim 3, characterized in that: The diameter of the alloy rod is 35-70 mm.

6. The method for preparing the alloy according to claim 3, characterized in that: The vacuum sintering purification is specifically as follows: heating the vacuum furnace from room temperature to 700-800°C within a time period of 0.5-2h, then keeping the temperature for 1-15h, continuing to heat up to 900-1000°C within a time period of 0.5-2h, keeping the temperature for another 1-15h, and finally heating up to 1000-1100°C within a time period of 0.5-2h, keeping the temperature for 1-15h.

7. Use of the alloy for synthesizing type IIa diamond according to any one of claims 1 to 2 in synthesizing type IIa diamond.

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