TW201714823A - Ultra high diamond boundary enhanced polycrystalline diamond compact - Google Patents

Abstract

A polycrystalline diamond compact disc which composed by one diamond layer and one tungsten layer. The diamond layer was synthesis under high temperature and high pressure that provides ultra-high diamond boundary enhancement. Nitrogen contained diamond powder and boron contained diamond powder were mixed in the diamond layer.

Description

Composite diamond material with high diamond bond density

The invention relates to a high-density composite diamond material structure and a manufacturing method thereof, which mainly utilizes the difference in heat-resistance characteristics between the chemical elements contained in the diamond, and replaces the traditional heat-resistant property with the novel boron-containing diamond micropowder with higher heat-resistance characteristics. The low nitrogen-containing diamond micropowder improves the problem that the fine-grained diamonds in the high-temperature and high-pressure synthesis process are not able to withstand the high temperature and the graphitization causes the catalyst to fail to sweep upwards and the diamond bond is greatly reduced.

As the diamond composite sheet continues to evolve, in order to improve the wear ratio and heat resistance of the tool, the synthesis of the diamond composite sheet is continuously improved.

In the earliest, Element Six added more metal powder (矽) to the nitrogen-containing diamond composite sheet to improve the heat resistance of the diamond composite sheet, but because the diamond concentration was reduced to 80%, the wear ratio was greatly reduced.

In addition, there is another product, which is to remove the surface catalyst (cobalt) after synthesizing the nitrogen-containing diamond composite sheet. The reason is that the nitrogen-containing diamond particles on the surface of the composite sheet are processed because the general nitrogen-containing diamond composite sheet is processed. The high temperature causes the catalyst to be reverse catalyzed into graphite, which in turn causes a decrease in the wear ratio. However, this method will make the surface of the composite sheet full of holes, and only the surface can remove the catalyst, and the same problem will be encountered when the surface is used up.

Therefore, the latest practice is to use different sizes of nitrogen-containing diamond particles during synthesis to obtain an optimized bulk density, thereby increasing the concentration of nitrogen-containing diamonds and preventing excessive catalyst from staying in the composite sheet. The disadvantage of this method is that fine-grain nitrogen-containing diamonds have a heat resistance lower than that of large-particle nitrogen-containing diamonds by 100-200 degrees, which may become graphite during the synthesis because of insufficient heat resistance and block the opportunity for the catalyst to sweep upwards. There is no chance of causing bonding between the nitrogen-containing diamond particles. When the cutting edge is ground, the large-grain diamond is pulled down due to the grinding resistance, causing chipping, which does not provide a better roughness of the workpiece.

Further, when a conventional nitrogen-containing diamond composite sheet is formed into a cutter, it is difficult to form and form, and has poor heat resistance during welding and a poor wear ratio.

The inventors have obtained "a boron-containing diamond composite sheet using high temperature and high pressure" in 2010 (Patent No.: ZL 2009 2 0069585.7). However, boron-containing diamonds are relatively expensive, and although they are more resistant to high temperatures, they are similar to general nitrogen-containing diamonds in diamond bond formation.

Accordingly, it would be desirable to provide a composite diamond material that is resistant to high temperatures and has a high diamond bond density to overcome the shortcomings of the prior art.

The invention utilizes a large particle nitrogen-containing diamond, which has similar characteristics to the temperature resistance point of the small particle boron-containing diamond, and simultaneously forms a diamond bond at the time of co-temperature, thereby forming the maximum amount of diamond bond by this principle.

The invention particularly provides a diamond composite sheet structure having high diamond bonding characteristics and a manufacturing method thereof, which utilizes a large particle nitrogen-containing diamond, which has similar characteristics to the temperature resistance point of a small particle boron-containing diamond, and simultaneously forms at the same temperature. Diamond bonding, the principle of forming the largest amount of diamond bonds, to achieve a high diamond bond density diamond composite.

According to the present invention, it is possible to surely overcome the disadvantage that the conventional nitrogen-containing diamond composite sheet is difficult to form and form when it is formed into a cutter, has poor heat resistance during welding, and has a poor wear ratio.

The detailed features and advantages of the present invention will be readily understood by

1‧‧‧Diamond layer

2‧‧‧hard layer

3‧‧‧Nitrogen-containing diamond powder

4‧‧‧Bonded diamond powder

Figure 1 is a side elevational view of the structure of the present invention.

Figure 2 is a top plan view of the structure of the present invention.

Figure 3 is a schematic view of the structure of the present invention showing the composition of the diamond layer.

Figure 4 shows a schematic diagram of the principle of the diamond bond of the present invention.

As shown in Figures 1 to 3, the present invention comprises a diamond layer 1 and a hard layer 2 which are combined to form a diamond composite sheet.

The diamond layer 1 is a diamond composite material comprising a nitrogen-containing diamond micropowder 3 and a boron-containing diamond micropowder 4. The size of the nitrogen-containing diamond particles in the nitrogen-containing diamond fine powder 3 is larger than that of the boron-containing diamond particles in the boron-containing diamond fine powder 4. The nitrogen-containing diamond particles preferably have a size of from 500 nm to 60 μm. The boron-containing diamond particles range in size from 100 nanometers to 20 microns. The hard layer 2 may be a hard alloy layer such as a tungsten carbide alloy layer, which can protect the diamond layer 1 from cracking due to too much internal stress upon cooling during the pressing process.

The nitrogen-containing diamond micropowder 3 and the boron-containing small diamond particles 4 have similar temperature resistance characteristics, and when they reach a temperature, they simultaneously form a diamond bond. Therefore, the nitrogen-containing diamond micropowder 3 and the boron-containing small diamond particles 4 are mixed in a certain ratio and sintered to form a maximum amount of diamond bonds to obtain a composite diamond material having a high diamond bond density.

Preferably, the volume ratio of the boron-containing diamond to the nitrogen-containing diamond is between 1:99 and 1:1.

In the composite sheet in which the diamond layer 1 and the hard layer 2 are combined, the thickness of the diamond layer is preferably about 0.1 cm to 10 cm. The thickness of the hard layer is preferably from about 0 cm to about 100 cm.

Figure 2 shows a schematic view of the finished product, preferably in the form of a sheet. Can be shaped as required. Figure 3 is a diamond composite sheet in which the detailed structure of the diamond layer 1 shows that the large-grain diamond and the small-grained diamond are closely packed together, and the intersection of the black line and the black line is the portion where the diamond bond is generated. Figure 4 shows the principle of the diamond bond of the present invention.

According to a preferred embodiment of the present invention, in the composite composite sheet, the diamond layer 1 can effectively fill the holes generated by the original single type of diamond micropowder due to the heat resistance temperature of the boron-containing diamond being higher than that of the nitrogen-containing diamond. The density is increased from 90% to 99%.

In the high-temperature and high-pressure synthesis, it is necessary to add a catalyst to make the diamond particles and the diamond particles meet the reverse catalysis of graphite, and then catalyze the graphite into diamonds in the subsequent synthesis process; the catalyst usually contains cobalt, which will work in a high temperature environment. The diamond is reverse catalyzed into graphite as the reaction in the synthesis process, and the volume is expanded to three times that of the original diamond, causing the bond portion of the diamond material to be crushed and broken, resulting in a decrease in tool life. By increasing the diamond bonding ratio and reducing the cobalt content as described in this patent, the life and heat resistance of the diamond material can be effectively improved.

According to the foregoing, the present invention utilizes a large particle nitrogen-containing diamond, which has similar characteristics to the temperature resistance point of a small particle boron-containing diamond, and simultaneously forms a diamond bond at the time of co-temperature, thereby forming the maximum amount of diamond bond by this principle, and Knowing technology brings great progress.

Therefore, the present invention also provides a method for manufacturing a composite diamond composite material and a cemented carbide layer composite sheet, comprising the following steps:

(1) mixing nitrogen-containing diamond micropowder 3 with boron-containing diamond micropowder 4 in a certain ratio And forming a mixture of diamond layers 1;

(2) combining the mixture with the hard layer 2 into a composite block;

(3) The composite block is placed in a special press for diamond, and sintered at a high pressure and high temperature to obtain a composite sheet of composite diamond material and hard layer. Among them, the sintering conditions are preferably a pressure of 5 to 7 GPa and a temperature of 1,400 to 1,600 °C.

(4) The diamond layer 1 of the composite sheet after the combination is smoothed and polished to obtain a finished product.

(5) The hard layer can be completely removed by post-treatment.

1‧‧‧Diamond layer

2‧‧‧hard layer

3‧‧‧Nitrogen-containing diamond powder

4‧‧‧Bonded diamond powder

Claims (6)

A composite diamond material and a hard layer synthetic diamond composite sheet having a diamond bonding structure sintered at a high temperature and high pressure, the diamond bonding structure comprising nitrogen-containing diamond particles and boron-containing diamond particles, wherein: the nitrogen-containing diamond particles Size, larger than the size of the boron-containing diamond particles. The composite diamond material according to claim 1, wherein the nitrogen-containing diamond particles have a size of from 500 nm to 60 μm; and the boron-containing diamond particles have a size of from 100 nm to 20 μm. The composite diamond material according to claim 1 or 2, wherein the volume ratio of the boron-containing diamond particles to the nitrogen-containing diamond particles is between 1:99 and 1:1. The composite diamond material according to claim 1, comprising: a diamond layer having the composite diamond material according to any one of claim 1 to claim 3; and a hard layer at the high temperature and high pressure Bottom is combined with the diamond layer. The diamond composite sheet of claim 4, wherein the diamond layer has a thickness of from about 0.1 cm to about 10 cm. The diamond composite sheet of claim 4, wherein the hard layer has a thickness of from about 0 cm to about 100 cm.