Performance advantages and disadvantages of diamond cutting tool materials

Performance advantages and disadvantages of diamond cutting tool materials
TFD is deposited to a thickness of 1mm or more even a few mm 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

Has good 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 smaller, better chemical stability, can be

Higher cutting speeds than the PCD cutting tools , 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.
All kinds of diamond tools and carbide tools performance comparison


TFD has been trimmed in wood processing tools and the tool has been widely used. Abroad has been TFD product (such as the 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 TFD

And part of the natural diamond tools PCD tools. Table 2 shows the PCD, TFD and synthetic single crystal diamond three performance comparison.


Shows, PCD, TFD (CVD thick) and synthetic single crystal diamond on each of the three performance characteristics, to a certain extent, can complement each other

according to different specific conditions to be used and their cost.
How to choose the diamond tool materials
Currently, single crystal diamond, PCD (or PCD / CC), and were successfully used for CVD diamond turning, boring tools, drills, reamers, milling cutters, molding

knives and other cutting tools Cutting part of the production materials.
Varieties of diamond material must be based on the nature of the material being processed and processing requirements to select, in addition to meet the technical

requirements, but also to meet the economic and environmental performance requirements.
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 field, PCD and PCD / CC for machining aluminum engine piston skirt, pin hole, cylinder block, transmission, carburetor and other wear parts. Most of these

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

Hard 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 from the effect, 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 is the world's hardest substance known, the actual use of proven, it is the processing of aluminum matrix composites

Best tool material.
With PCD 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. Shows the drilling process with 20% of PCD tools

SiCυ of aluminum matrix composite spiral pump casing application examples.


With PCD tool drilling process 20% SiCυ of aluminum matrix composites
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.
De Beers company produced 002,010 and 025 PCD inserts are several, average grain sizes are 2μm (fine grain), 10μm (in grain) and 25μm (coarse grain). The grain

size, the better the greater the wear, tool life, the higher the rough cutting edge

, Edge of poor quality, precision cutting tools made difficult; mechanical processing of grain generally used as generic brands; fine-grained tool cutting edge edge

edge radius is small, easy to process a good surface quality. Thus continue to refine the current grain polycrystalline, and have been very 1μm

To have 0.5μm or less fine-grained, to be based roughing and finishing processes, such as different requirements, use of different grain sizes.
Single crystal diamond tool materials
Single-crystal diamond and PCD (or PCD / CC) and PCD (or PCD / CC) and between CVD diamond can complement each other well, there are some cross-cutting applications.
Single crystal diamond cut surface of the continuous workpiece, and the workpiece with the PCD cutting surface showing discontinuity of microns, so PCD is only

suitable for general machining area, there are special requirements for some polishing process, prepared as Al2O3 mirror

Surface, only the use of natural diamond crystal to achieve the desired surface roughness and dimensional tolerances.
Natural diamonds are rare large size diamond, but the large size of synthetic diamond has now become possible. Its processing with high wear layered wood, its

performance is superior to PCD diamond cutting edge will not cause premature passivated. In the processing of aluminum matrix composites

When using the PCD can also be used TFD (CVD thick). Figure 3 shows two kinds of a PCD and diamond machining TFD 40% SiCυ A356MMC wear curves of the tool material.

Figure 3 using the cutting test conditions: cutting speed 400m/min, amount of feed

0.05mm / r, depth of cut (cutting depth) 0.5 mm, plus cutting fluid. According to experiments, processing 40% SiCυ matrix composites, using thick-film diamond TFD

best effect, PCD025 followed, PCD002 tool life minimum.


PCD and CVD diamond blade machining 40% SiCυ/A365 metal matrix composites with abrasive side cutting time curve.
Since the various diamond face in adapting to the complementary nature of processed diamond tool range has been expanded to replace synthetic diamond powder natural diamond,

CVD diamond substitute PCD diamond trends become apparent. Are thus cutting into a

Achieve efficient and economical processing of a new era, and its degree of substitution depends on both technical and economic factors, especially the blade forming,

grinding, and welding degree of difficulty will directly affect the price and performance of diamond tools.
Typically PCD tool for roughing and requires a higher fracture toughness tool production, CVD single crystal diamond tool thick and are used for high-speed finishing

and semi-finishing.