The electroplated diamond grinding wheel

Electroplated synthetic diamond grinding wheel advantages and disadvantages:
Benefits:
① plating process is simple, less investment, ease of manufacture;
② without dressing, easy to use;
③ monolayer structure determines it can reach very high operating speed, the current foreign countries have been as high as 250 ~ 300m / s;
④ Although only a single layer of diamond, but there is still enough life;
⑤ For high accuracy, roller wheels, electroplated unique manufacturing method.
Precisely because of these advantages, plating wheel speed, ultra-high speed grinding occupy undisputed dominance.
Disadvantages:
Metal coating and the substrate and the surface is not kept firmly binding the abrasive chemical metallurgical bonding, actually only be mechanically entrapped

abrasive wheels coating metal inlay, thus gripping force is small, efficient grinding diamond particles heavier load shedding (or plating flaking ) which lead to an overall

failure;

To increase the holding force must be increased coating thickness, and the results highly abrasive bare chip space is reduced, wheel prone to clogging, the cooling

effect is poor, prone to burn the workpiece surface. Currently electroplated grinding wheel manufacturing requirements has not been achieved by optimized processing

conditions set

The best interest of the grinding wheel topography, single electroplated diamond grinding these inherent drawbacks will be significantly limited its efficient grinding

applications.

The resin diamond grinding wheel

Feature
Diamond resin grinding wheel has a good polishing effect, grinding wheel sharp, easy to plug, the specific features are as follows:
1 high grinding efficiency while consuming relatively slow grinding wheel;
(2) self-sharpening, grinding, heat a small, easy to plug, reducing the grinding burn occurs when the phenomenon of work;
3 wheel has a certain degree of flexibility will help to improve the surface roughness, mainly used for grinding, semi-fine grinding, knife grinding, polishing and

other processes;
4 synthetic diamond resin grinding is low temperature curing, short production cycle, equipment and supply process is relatively simple; due resin liquid, easy to shape complex

plane of the wheel.
Use
Diamond resin grinding wheel, high hardness, strength, Abrasive grinding ability, mainly used for grinding high and hard alloys, non-metallic materials, cutting hard and

brittle carbide, non-metallic minerals. Such as cemented carbide, ceramic, agate, optical glass, semiconductor materials and wear cast

Iron, stone and so on.

The performance characteristics of polycrystalline diamond tools

Diamond tool with high hardness, high compressive strength, thermal conductivity and good wear resistance and other characteristics, can be obtained in a high-speed

cutting machining accuracy and processing efficiency. Above characteristics of diamond tools is determined by the state of the diamond crystal. In the diamond crystal,

the carbon atoms of the four valence electrons enter the tetrahedral bond, each carbon atom with four adjacent atoms form a covalent bond, and then form a diamond

structure, the structure is very strong binding force and direction, so that the diamond has a very high hardness. As polycrystalline diamond (PCD) of varying

orientation of the structure of fine grain diamond sintered body, although the added binding agent, the hardness and wear resistance is still lower than the single

crystal diamond. However, due to the performance of polycrystalline diamond sintered body is isotropic, so easy to split along a single cleavage plane. Polycrystalline

diamond cutting tools materials, the main performance indicators: ① polycrystalline diamond's hardness up to 8000HV, is 80 to 120 times carbide; ② thermal

conductivity of polycrystalline diamond 700W/mK, as carbide 1.5 ~ 9 times or higher than PCBN and copper, so rapid heat transfer polycrystalline diamond tools; ③ the

coefficient of friction of polycrystalline diamond is typically only 0.1 to 0.3 (the friction coefficient of carbide 0.4 to 1), the polycrystalline diamond tools can

significantly reduce the cutting force; ④ polycrystalline diamond thermal expansion coefficient of only 0.9 × 10 -6 ~ 1.18 × 10 -6, equivalent to only carbide 1/5,

so the thermal deformation of polycrystalline diamond tools, high precision ; ⑤ polycrystalline diamond tools and non-ferrous metals and non-metallic materials, the

affinity between the small chip in the process is not easy to bond formed on the tip BUE.

Synthetic polycrystalline diamond

Synthetic polycrystalline diamond of the diamond with a binding agent at high temperature under high pressure sintered diamond polymer which has a very high heat

resistance and high thermal stability. Widely used in manufacturing petroleum, geological drill bits, diamond processing and machining tools.
Classification
Polycrystalline Diamond for petroleum and geological drill into the TSP series and for diamond processing of polycrystalline diamond series:
Synthetic polycrystalline diamond TSP: ① the diamond mainly inert binding agent and the diamond particles made of high temperature and pressure conditions. At the

same time due to the thermal expansion coefficient of the binder close to the diamond, so the heat resistant temperature of 1200. C or so. ② It has high wear ratio,

also known as thermally stable polycrystalline compared to the cost of natural stone at a very low cost, is the production of petroleum geology drill the ideal

material. The same can also be used for grinding.
synthetic diamond polycrystalline diamond polycrystalline diamond: ① mainly by diamond and binding agent in the high temperature / high pressure sintering. ② It is much

lower than the wear than the TSP series, compared to the natural diamond has a higher grinding efficiency, with unparalleled price advantage, has become the inevitable

rough diamonds, is very conducive to a variety of processes of grinding and polishing . Polycrystalline diamond can precisely control the wear ratio, can adapt to

different processing requirements. Since all manufacturers use different formulations and processes, so the production process and durable effect is different.
Feature
Polycrystalline Diamond PCD: hardness high wear resistance and impact toughness.
Polycrystalline diamond TSP: ① has good thermal stability and higher impact strength and better wear resistance; ② than it consumes up to 30,000 ~ 100,000; ③ can

meet a variety of complex underlying drilling needs.
Use
Polycrystalline Diamond Polycrystalline Diamond Series (Po polycrystalline):
Since hardness for natural diamond polishing and edge to the machining tool. Oil drill cutting elements, suitable for soft to medium hard formation drilling, machining

tool can also be used as a cutting edge for cutting non-ferrous metals and non-metallic materials. Products can be processed into the desired size and shape of the

user.
Polycrystalline diamond TSP Series:
For oil drilling, geological exploration, drilling small diameter polycrystalline insurance cost compared to natural diamond and very inexpensive, high wear

resistance. Products can be processed into the desired size and shape of the user.
Because two kinds of polycrystalline polycrystalline diamond and TSP hardness and wear resistance effect is not the same, so the degree of processing polycrystalline

diamond is very different.
Shape
Polycrystalline diamond with a triangle, square, rectangular, cylindrical, both ends of the arc-shaped, and its diversification tool for a variety of drilling and

geological requirements.

Polycrystalline Diamond Compact Drill

Brief introduction
The composite sheet was set shape is welded to a circular cylinder on the cutting tool, the cutting insert mounted on a drill bit body, a PDC bit. Than natural Diamond blade

drill bits PDC bits, low cost, but only for soft to medium hard formations. PDC bits in the early 1970s after the success of the manufacture and use, rapid

development, it is at a lower pressure and a high speed drill, drill footage height, unit footage low cost. China Oilfield use some polycrystalline diamond composite

sheet inserts welded on the blade, also received good results.
Classification
Geological exploration with PDC drill.
Mainly used in geological prospecting exploration PDC drill for soft to medium-hard rock, some manufacturers are now new research and development of new composite

sheet can be applied to ten hardness of rock.
Coal drilling using PDC drill.
Is mainly used in coal seam drilling on the excavation. Generally speaking relatively soft coal formations, PDC drill have been widely used, such as anchor bit, three

-wing drill and so on.
PDC drill bit with oil exploration
Mainly used in oil and gas drilling using the drill bit. At present, the oilfield PDC drill is all PDC drill inside the highest cost, requiring the highest. Can be

said that PDC drill inside the nobility.

Polycrystalline diamond tools

As a superhard diamond cutting tool materials have been used for hundreds of years of history. In the tool development process, from the nineteenth century to the mid

-twentieth century, high-speed steel tool material as the main representative; 1927 Germany developed the first carbide tool material and is widely available; nineteen

fifties, Sweden and USA were synthesized diamond cutting tool with superhard materials from entering the representative period. 1970s, people were synthesized using

high pressure synthesis of   polycrystalline diamond (PCD), to solve the natural diamond scarce and expensive problems, make the diamond tool applications extended to

aviation, aerospace, automotive, electronics, stone other fields.
Features
Diamond tool with high hardness, high compressive strength, thermal conductivity and good wear resistance and other characteristics, can be obtained in a high-speed

cutting machining accuracy and processing efficiency. Above characteristics of diamond tools is determined by the state of the diamond crystal. In the diamond crystal,

the carbon atoms of the four valence electrons enter the tetrahedral bond, each carbon atom with four adjacent atoms form a covalent bond, and then form a diamond

structure, the structure is very strong binding force and direction, so that the diamond has a very high hardness. As polycrystalline diamond (PCD) of varying

orientation of the structure of fine grain diamond sintered body, although the added binding agent, the hardness and wear resistance is still lower than the single

crystal diamond. However, due to the performance of polycrystalline diamond sintered body is isotropic, so easy to split along a single cleavage plane.
Application
Polycrystalline diamond tools for industrial countries study carried out earlier, its application has been more mature. The first time since 1953 in Sweden since the

synthetic diamond , polycrystalline diamond tools for cutting a lot of research to get results, polycrystalline diamond tool application and usage is expanding rapidly.

By turning around early to drilling, milling expansion. Organized by the Japanese conducted a survey of about superhard cutting tool: polycrystalline diamond tools

people use the key consideration is based on the polycrystalline diamond tool machined surface accuracy, dimensional accuracy and tool life and other advantages. PDC

synthesis technology has been greatly developed.
Domestic polycrystalline diamond tool market with the level of development of tool technology is also expanding. At present, China First Automobile Group has over one

hundred point of use polycrystalline diamond tools, and many companies are using wood-based panels polycrystalline diamond tools for wood processing. The application

of polycrystalline diamond tools for its further promote the design and manufacture technology. Domestic Tsinghua University, Dalian University of Technology, Huazhong

University of Science, Jilin University, Harbin Institute of Technology are on active research in this area. Engaged in research and development of polycrystalline

diamond tools, production of a Shanghai Shubohate, Zhengzhou New Asia, Nanjing, Leitz, Shenzhen Runxiang, Chengdu Tool Research Institute and dozens of units.

Currently, the processing of polycrystalline diamond tools range from traditional metal cutting extended to stone processing, wood processing, metal matrix composites,

glass, ceramics and other materials processing engineering. In recent years, through the analysis of the application of polycrystalline diamond tools visible,

polycrystalline diamond tools are mainly used in the following two aspects: ① difficult to machine non-ferrous materials processing: with ordinary non-ferrous

materials difficult to machine tooling, often generating tool easy to wear, processing efficiency and low defects, and polycrystalline diamond cutting tool can exhibit

good processability. Such as the use of polycrystalline diamond cutting tool can be effectively and processing of new materials, engine pistons - hypereutectic silicon

aluminum (mechanism of the materials processing has made breakthroughs). ② difficult to machine processing of non-metallic materials: polycrystalline diamond cutting

tool is very suitable for stone, hard carbon, carbon fiber reinforced plastics (CFRP), artificial board and other difficult to machine processing of non-metallic

materials. If Huazhong University in 1990 to achieve a glass with polycrystalline diamond cutting tools; currently laminate flooring and other wood-based panels (eg

MDF) is a widely used, with a polycrystalline diamond cutting tool machining these materials can effectively prevent the tool wear and other defects .
Manufacturing Process
PCD cutting tool manufacturing process consists of two stages: ① polycrystalline diamond compact manufacturing: Polycrystalline Diamond Compact is made from natural

or synthetic diamond powder and binder (which contains cobalt, nickel and other metals) by a certain percentage in high temperature (1000 ~ 2000 ℃), pressure (5 to

100,000 atmospheres) for sintering. In the sintering process, due to binding agent is added, between the diamond crystals to form TiC, SiC, Fe, Co, Ni, etc. as a main

component with the bridge, the diamond crystals to form a covalent bond with the bridge mounted on the skeleton. The composite sheet is usually made from a fixed

diameter and the thickness of the disc, the need for sintering the composite sheet for grinding and polishing and other appropriate physical and chemical treatment. ②

polycrystalline diamond blade processing: the processing of polycrystalline diamond blade includes a composite sheet cutting, welding blade, blade sharpening and other

steps.
Cutting process
Since Polycrystalline Diamond has high hardness and wear resistance, it must use a special processing technology. Currently, the processing Polycrystalline Diamond

Compact mainly EDM wire cutting, laser processing, ultrasonic machining, high pressure water jet technology, such as several methods polycrystalline diamond compact

cutting process comparison
Process methods - Process Features
EDM - highly concentrated pulse discharge energy, a powerful explosive discharge of the polycrystalline diamond material of the metal melt, some diamond graphitization

and oxidation, and some diamond shedding, good technology, high efficiency
Ultrasonic machining - Machining efficiency is low, diamond powder consumption, dust pollution
Laser processing - non-contact processing, high efficiency machining deformation, poor process
In the processing method, EDM better results. Polycrystalline diamond composite bridges in the presence of EDM composite sheet becomes possible. In conditions of a

working fluid, a pulse voltage to the electrode near the metal working fluid is formed at the discharge channel, and the local produce sparks, polycrystalline diamond

instantaneous high temperature can melt off, thereby forming the desired triangular, rectangular or square head blank. EDM Polycrystalline Diamond efficiency and

surface quality by cutting, polycrystalline diamond size, thickness and electrode quality and other factors, including reasonable choice of cutting speed is critical

experiments show that increasing the cutting speed will be reduced surface quality, and cutting speed is too low will produce "arch wire" phenomenon and reduce cutting

efficiency. Increase will reduce the thickness of polycrystalline diamond blade cutting speed.
Welding
PCD composite sheet and the cutter body binding mode in addition to the use of mechanical clamping and bonding methods, mostly by brazing way Polycrystalline Diamond

Compact suppressed in the cemented carbide substrate. Welding methods include laser welding, vacuum diffusion welding, vacuum brazing, high frequency induction

brazing. Currently, less investment, low cost high frequency induction heating brazed polycrystalline diamond blade welding is widely used. The blade welding process,

the welding temperature, the choice of flux and solder alloy weld will directly affect the performance of the tool. During the welding process, the welding temperature

control is very important, such as welding temperature is too low, then the weld strength is not enough; such as welding temperature, polycrystalline diamond

graphitization easy and may lead to "over-burning" effect Polycrystalline Diamond Compact with the carbide substrate combination. In the actual process, according to

the holding time and the degree of difficulty of polycrystalline diamond red controlled soldering temperature (generally should be lower than 700 ℃). Use more foreign

high-frequency welding automatic welding process, welding, high efficiency, good quality, enabling continuous production; country is to use more manual welding,

production efficiency is low, the quality is not ideal.
Grinding process
The high hardness of polycrystalline diamond material removal rate so low (even only one ten thousandth of carbide removal). Currently, polycrystalline diamond tool

sharpening process is mainly made of resin bonded diamond grinding wheel. As polycrystalline diamond abrasive wheel and grinding are two hardness between similar

interaction between the materials, so the grinding more complicated laws. For high granularity, low-speed wheel, using a water-soluble coolant can improve the

efficiency of polycrystalline diamond grinding and grinding accuracy. Grinding binder type should be selected as the grinding and processing conditions. Since

discharge grinding (EDG) technology is almost free from hardness of workpiece to be ground, so the use of polycrystalline diamond grinding EDG technology has great

advantages. Some complex shapes polycrystalline diamond tools (such as woodworking tools) are also on this flexible grinding grinding process has a huge demand. As

technology continues to evolve EDG, EDG polycrystalline diamond grinding technology will become one of the main development direction.
Polycrystalline diamond size
Polycrystalline diamond size selection and tool processing conditions, such as design for finishing or super-finishing tool should be used in high strength, good

toughness, good impact resistance, fine-grained polycrystalline diamond. Coarse grain polycrystalline diamond tools can be used for general roughing. Polycrystalline

diamond material particle size for tool wear and breakage significantly influence the performance. Studies show that: the greater the number of polycrystalline diamond

size, tool wear resistance is stronger.
Blade thickness
Typically, polycrystalline diamond composite sheet thickness is about 0.3 ~ 1.0mm, carbide layer with a total thickness of about 2 ~ 8mm. Thin polycrystalline diamond

blade thickness is conducive to EDM. Polycrystalline Diamond Compact welding and cutting material, carbide layer thickness can not be too small, the combination of the

two materials in order to avoid stress difference between the surface and cause delamination.
Structural Design
Polycrystalline diamond tool geometry parameters depend on the workpiece position, tool materials and structures and other specific processing conditions. As

polycrystalline diamond tools commonly used in finishing a workpiece, the cutting thickness is small (and sometimes equal to the radius of the tool cutting edge), are

micro-cutting, so after the cutting angle and the subsequent processing quality has significant effect on the face of the smaller rear angle, the higher the quality of

the flank polycrystalline diamond tools for improving the processing quality can play an important role.
Polycrystalline Diamond Compact connection with Arbor methods include mechanical clamping, welding, indexable variety of ways, their characteristics and applications

are shown in Table 2.
Polycrystalline Diamond Arbor connection with the characteristics and applications
Connection - Features - Applications
Mechanical clamping - from standard cutter body and can be made into various collections consisting blade angle can be changed with a quick and easy regrinding

advantages - small machine tools
Welded - compact, easy to make, can be made small tools - special tools or difficult to machine clip tool for small machine tools
Machine folder Welding - Welding in knife blade head, you can use standard shank for easy sharpening and adjusting head position - automatic machine tools, CNC machine

tools
Indexable - compact, reliable clamping, without re-grinding and welding, can save auxiliary time, improve tool life - ordinary general machine
Cutting parameters
Polycrystalline diamond cutting tool cutting parameters on the impact of
Cutting speed
Polycrystalline diamond tools in high spindle speed for cutting, but cutting speed changes on processing quality can not be ignored. Although high-speed cutting can

improve processing efficiency, but in high-speed cutting conditions, cutting temperature and cutting force increases can tip breakage, and make the machine vibrate.

Processing of different workpiece materials, polycrystalline diamond cutting tool is reasonable also different, such as Al2O3 laminate flooring milling reasonable

cutting speed 110 ~ 120m/min; turning SiC particle reinforced aluminum matrix composites and ceramic works reasonably silicon oxide cutting speed is 30 ~ 40m/min.
Feed
Polycrystalline diamond tools such as the feed is too large, the workpiece residual geometric area will increase, resulting in increase of surface roughness; if the

feed is too small, the temperature rise will cause the cutting, the cutting life is reduced.
Cutting depth
Increased PCD tool cutting force will increase the depth of cut, cutting heat increased, thereby increasing tool wear, impact tool life. In addition, the cutting depth

increases likely to cause PCD tool chipping.
Different levels of granularity of polycrystalline diamond tools in different processing conditions processing of different workpiece materials, the performance of the

cutting are not the same, it should be determined according to the specific processing conditions of the actual cutting parameters PCD tool.
Failure Mechanism
Mainly in the form of tool wear abrasive wear, adhesive wear (cold welding wear), diffusion wear, oxidation wear, thermal wear. Polycrystalline diamond tool failure

modes differ with traditional tools, mainly for the polycrystalline layer is damaged, adhesive wear and diffusion wear. Studies have shown that using polycrystalline

diamond tools when machining metal matrix composites, mainly in the form of its failure to adhesive wear and defects caused by a microscopic diamond grain

intergranular cracks. In the processing of high hardness, high brittle material, bonded polycrystalline diamond tool wear is not obvious; contrast, in the processing

of low brittle materials (such as carbon fiber reinforced material), the increase in tool wear, adhesive wear dominant time effect.

PCD and PCD / CC material

PCD and PCD / CC is the most commonly used in the production of diamond material, it applies not only usually machining fields, but also widely used in automobiles,

motorcycles, high-speed trains, petroleum, chemical, construction, wood processing, and aerospace and other industrial sectors. In the automotive and motorcycle

Car field, PCD and PCD / CC suitable for machining aluminum engine piston skirt, pin hole, cylinder blocks, transmission, carburetor and other wear parts. Most of

these components are relatively high silicon content (Si> 12%) of aluminum composite material of high hardness of the hard

Mass particles (such as high hardness of SiC-3000 ~ 3500HV) distributed in the alloy matrix, and if the abrasive wheel as the cutting edge of the tool be abrasion and

impact action from, leaving the cutting edge wear quickly. The higher the hardness of hard particles, the larger the size of particles,

The greater the number of particles, then the tool wear faster. Therefore, it is difficult using conventional machining of carbide cutting tools, tool life is very low

or impossible to use. Diamond blade is the world's hardest substance known, the actual use of proven, it is the processing of aluminum matrix composites

Best tool material.
With polycrystalline diamond machining aluminum matrix composites, its cutting speed of up to 800 ~ 1000m/min, tool life is several times higher than the carbide or even several

times the surface roughness value of up to Ra 0.025 ~ 0.012μm. Figure 2 shows the drilling process with PCD tools

20% SiCυ of aluminum matrix composite spiral pump casing application examples.
With PCD (or PCD / CC) tooling carbon fiber and glass fiber reinforced plastic (FRP), the chip into a powder, cutting temperature is low, and the length of class K

carbide cutting tool 10 times, and not to hard wear carbide tool 1/3.
PCD (or PCD / CC) also applies to the processing tool after a burn-resistant carbide and non-metallic materials, such as ceramic, rubber, graphite, glass and various

wear-resistant timber.
PCD tool performance depends primarily on its application and the process involved, but the choice of the appropriate grade and particle size can also affect it.

Different varieties of PCD inserts, due to its composition of different cutting is very different, the election

Use should be noted.
Currently PCD inserts Carbide did not have a unified international classification, each has its own production plant varieties and grades, to be used to select the

reference sample manufacturers.

CVD diamond

CVD diamond is a diamond material of high wear resistance of pure, non-binding agent, which is at low pressure (<0.1MPa) prepared under. CVD diamond films are coated

CVD (CD) and CVD thick (TFD) forms.
CD is a CVD (chemical vapor deposition) process, the carbide substrate (K type alloy used) is deposited to a thickness of about 10 ~ 30μm, composed of a

polycrystalline diamond film is made. Matrix is ​​made easy due to complex shapes, it applies to the complex geometry of the knife

Tools, such as taps, drills, end mills and band chipbreakers indexable inserts and so on. International instruments the market have a CD tool products, such as the

Swedish Sandvik's CD1810 and the United States Kennametal's KCD25, mainly for non-ferrous metals and non-metallic materials with high

Speed ​​precision machining, tool life than uncoated carbide increased nearly tenfold or even several times. However, the tool is not suitable for processing of metal a

CD-based composite materials, composite materials because of hard particles in a very short period of time will be worn tool surface layer of coating, the

Although the price of the tool with CD PCD cutting tool to be lower than similar, but due to the diamond film and the adhesion between the matrix material is small, so

limiting its widespread application.
TFD is deposited to a thickness of 1mm or more even a few mm (De Beers company deposition thickness up to 5mm) thick non-diamond substrate, according to need and then

cut to the shape of thick pieces, then welded carbide formed composite blades or knives. TFD good

The overall performance, it is not natural diamond anisotropy shortcomings, because no metal binding agent, low impurity content, purity close to 100%, the hardness

and thermal conductivity higher than that PCD (see Table 1), the friction factor is smaller, better chemical stability, can be compared

PCD cutting tool is higher, but the toughness is slightly less than the PCD, because of the non-conductive, it can not be used for electrical discharge machining (EDM)

technology. TFD has been trimmed in wood processing tools and the tool has been widely used. TFD existing foreign products (such as De

Beers company DIAFILM brand). Although TFD tools more expensive, but with the improvement of the manufacturing process, the future is expected to replace expensive

natural TFD Diamond blade and part of the PCD tool. Table 2 shows the PCD, TFD and synthetic diamond single crystal diamond three

Performance comparison.

Synthetic polycrystalline diamond

Synthetic polycrystalline diamond (PCD) and synthetic diamond polycrystalline diamond and carbide composite blade (PCD / CC)
PCD is at high temperature (about 1800 ℃), pressure (5 ~ 6MPa), the use of cobalt and other metal binding agent to a number of polycrystalline diamond crystal powder

polycrystalline material, although slightly lower than the hardness of a single crystal diamond, but it is randomly oriented polymeric diamond grains, an isotropic

, Can be used as a cutting tool sharpening arbitrarily oriented, without natural diamond that must be selected as the best cleavage plane as a rake. In cutting, the

cutting edge is very sensitive for accidental damage, wear resistance is also strong, long stay sharp cutting edges,

Can be used when a high processing speeds and large depth of cut (to eat deep), the service life is generally higher than WC-based cemented carbide tool 10 to 500

times, and because the PCD conductive metal binding agent, such PCD easy to cut to shape, and is a rich source of raw materials,

Its price is only natural diamond fraction of a few tenth to ten, has become a traditional WC-based cemented carbide cutting tools, high-performance alternatives.
PCD inserts to improve the toughness and weldability in the cemented carbide substrate, sintered or pressed on the surface of 0.5 ~ 1mm thick layer of the composition

of PCD diamond composite blade (PCD / CC). PCD / CC welding or machine folder available way of making knives. Due to its good weldability, regrinding

Easy, low cost, it is widely used. Hereupon, PCD and PCD / CC sharp cutting edge of the tool and are not as good surface quality single crystal diamond, while its

workability is poor, the grinding ratio is small, it is difficult according to the geometry of any head shape, has not yet

Easy to manufacture with chipbreakers indexable end mills and other geometric shapes and complex products.

The main component of synthetic diamond

synthetic diamond commonly known as "diamond." That is, we often say that the diamond, it is a mineral composed of pure carbon, is the hardest substance in nature.
The composition and crystal structure of diamond polycrystalline diamond mainly of carbon (C), the amount of C 96% -99.9%. Even a pure diamond is 0.001% of the impurities. Impurities

in the diamond component has a Si, Al, Ca, Mg, Mn, Ti, Cr, N and so on. Other than N, the other miscellaneous

Quality mineral inclusions are usually in the form of diamonds often contain magnetite, ilmenite, pyrope, chrome diopside, olivine, graphite and other mineral

inclusions. Nitrogen (N) is an important impurity in diamond components, N in the diamond crystal structure composed of various defects

Centers can be a single N, A center, B centers, N3 small wafer or the like form. According to the N content and coalescence forms can be divided into diamond type Ⅰ

and Ⅱ. Ⅰ type diamond N content higher (0.05% -0.3%). Type Ⅰ a small diamond chips N3 N to form, Ⅰ b

N-type diamond paramagnetic dispersed state exists in the way. Ⅱ type diamond containing the N of less (<0.05%), N exist in a free state. Ⅰ and type Ⅱ diamonds in

certain physical properties differ. Most natural diamonds are type Ⅰ diamonds. Diamonds equiaxed

, The crystal structure of fcc lattice with lattice parameters a ° = 3.56A (1A = 1mm / 1 ten million) (see left). C atoms are located at the top corners cubic unit

cell of eight and six face center, and in its eight small standing white checkered center half is distributed with four C atoms, each of the original C

Sub are four C atoms and the surrounding connected between every two adjacent C-atoms are equal distance (1.54A). This structure formed between the C atom of an

extremely strong covalent bond, chemical bond to separate this large amount of energy to be given. This determines the diamond has some special

Special properties, such as high hardness and chemical stability. The most common crystalline diamond octahedral, rhombic dodecahedron followed, less common is the

cube.

Synthetic diamond market conditions

With the early 1970s, massive synthetic diamond and the emergence of the mid 1980s, the diamond film to enter the market, and the significant decline in the cost of

production of synthetic diamond, diamond sharp increase in consumption, the current international market for synthetic diamond total of

Demand has more than one billion kt. Consumption is mainly stone processing, concrete cutting, machining, glass processing, geological drilling, oil and gas

exploration and electronic industrial processing semiconductor materials, production drawing dies and so on.
20th century, 90 years ago, our main market is the synthetic diamond machinery, geology, petroleum, drilling and other industries, to account for about 60% to 70%. In

the 1990s, due to the development of stone processing industry, led the development of synthetic diamond industry for Stone

Timber processing industry, the number of synthetic diamond straight up, now its consumption of synthetic diamond production accounts for about 70% or so. In recent

years, China's oil and gas exploration continued to heat up, especially in the western development on oil exploration, natural gas, etc.

The construction of large projects, strong demand for diamond tools. In recent years, according to the geological drilling assignments, hydropower, coal chemical and

other statistical data, we estimate the market demand for diamond drill geology is estimated at 15 to 200,000, consume about 350 ~ 4.5 million diamond

Carats. PCD drill domestic oil drilling composite sheet production can not meet demand, and low quality, currently need to import. Therefore, the oil and gas industry

is a promising diamond market.
 2000 China's auto production reached 2,000,000, the 2005 car production will reach 3.5 million. But so far, the domestic diamond tool machining difficult to meet the

automotive industry, the introduction of a large number of complete sets of automatic production line needs, and imported from abroad. Therefore

, The domestic market is the machining tool has the potential for future expansion and occupation of the market.
In recent years, China's communications industry, ceramic industry developed rapidly, and the development prospects of a better future, therefore, drawing film and

ceramics with polycrystalline diamond tools will greatly increase the potential market is large. At present, China actively explore the international diamond market. As appropriate

Chang Black Whirlwind brand diamond saw blades base for export to Germany is expected to reach $ 1 million, accounting for 18% of all products to 20%; while the

production of diamond tools of the old enterprises IOL Institute laser welding diamond saw blade exports to the U.S. are expected to exceeded 10,000.