A diamond tool is a cutting tool with diamond grains fixed on the functional parts of the tool via a bonding material or another method. As diamond is a superhard material, diamond tools have many advantages as compared with tools made with common abrasives such as corundum and silicon carbide.
For more information, please visit Leading Diamond Tools.
History
[
edit
]
In Natural History, Pliny wrote "When an adamas is successfully broken it disintegrates into splinters so small as to be scarcely visible. These are much sought after by engravers of gems and are inserted by them into iron tools because they make hollows in the hardest materials without difficulty."[1]
Advantages
[
edit
]
Diamond is one of the hardest natural materials on earth; much harder than corundum and silicon carbide. Diamond also has high strength, good wear resistance, and a low friction coefficient. So when used as an abrasive, it has many obvious advantages over many other common abrasives.
Diamond can be used to make grinding tools, which have the following advantages:
Categories
[
edit
]
There are thousands of kinds of diamond tools. They can be categorized by their manufacturing methods and their uses.
Categories by manufacturing method
[
edit
]
According to their manufacturing methods or bond types, diamond tools can be categorized to the following way:
Categories by use
[
edit
]
If categorized by use, there are diamond grinding tools, diamond cutting tools (e.g., diamond coated twist drill bits), diamond drilling tools, diamond sawing tools (e.g., diamond saw blades), diamond drawing dies, etc.
Applications
[
edit
]
Applicable materials
[
edit
]
Diamond tools are suitable to process the following materials:
As diamonds can react with Fe, Co, Ni, Cr, V under the high temperatures generated in the grinding processes, normally diamond tools are not suitable to process steels, including common steels and various tough alloy steels, while the other superhard tool, cubic boron nitride (CBN) tool, is suitable to process steels. The tools made with common abrasives (e.g. corundum and silicon carbide) can also do the task.
Applied domains
[
edit
]
Diamond tools are used in the following domains:
Besides what are listed above, there are also other domains where diamond tools are applied, for example, in medicine, Venezuelan scientist Humberto Fernandez Moran invented the diamond knife for use in delicate surgeries in 1955.
Apart from its use as an abrasive due to its high hardness, diamond is also used to make other products for its many other good properties such as high heat-conductivity, low friction coefficient, high chemical stability, high resistivity and high optical performances. These applications include coatings on bearings and CDs, acting as lens and thermistors, making high-voltage switches and sensors, etc.
Diamond dressers consist of single-point or multipoint tools brazed to a steel shank, and used for the trueing and dressing of grinding wheels. The tools come in several types, including: grit impregnated, blade type, crown type, and disc type. The advantages of multipoint over single-point tools are:
Further information on synthetic diamond: Polycrystalline diamond
Polycrystalline diamond (PCD) is formed in a large High Temperature-High Pressure (HT-HP) press, as either a diamond wafer on a backing of carbide, or forming a "vein" of diamond within a carbide wafer or rod.
Most wafers are polished to a mirror finish, then cut with an electrical discharge machining (EDM) tool into smaller, workable segments that are then brazed onto the sawblade, reamer, drill, or other tool. Often they are EDM machined and/or ground an additional time to expose the vein of diamond along the cutting edge. These tools are mostly used for the machining of nonmetallic and nonferrous materials.
The grinding operation is combined with EDM for several reasons. For example, according to Modern Machine Shop,[citation needed] the combination allows a higher material removal rate and is therefore more cost effective. Also, the EDM process slightly affects the surface finish. Grinding is used on the affected area to provide a finer final surface. The Beijing Institute of Electro-Machining[citation needed] attributes a finer shaping and surface geometry to the combination of the two processes into one.
The process itself is accomplished by combining the two elements from each individual process into one grinding wheel. The diamond graphite wheel accomplishes the task of grinding, while the graphite ring around the existing wheel serves as the EDM portion. However, since diamond is not a conductive material, the bonding in the PCD work piece must be ample enough to provide the conductivity necessary for the EDG process to work.
Polycrystalline diamond tools are used extensively in automotive and aerospace industries. They are ideal for speed machining (9000 surface feet per minute or higher) in tough and abrasive aluminum alloys, and high-abrasion processes such as carbon-fiber drilling and ceramics. The diamond cutting edges make them last for extended periods before replacement is needed. High volume processes, tight tolerances, and highly abrasive processes are ideal for diamond tooling.
Polycrystalline diamond compacts
[
edit
]
In the late 1970s, General Electric pioneered the technology of polycrystalline diamond compacts (PDCs) as a replacement for natural diamonds in drill bits.[4] PDCs have been used to cut through crystalline rock surfaces for extended periods of time in lab environments, and these capabilities have now been implemented in harsh environments throughout the world.
As of August 2000, the U.S. Department of Energy claimed that nearly one-third of the total footage drilled worldwide is being drilled with PDC bits, with a claimed savings of nearly $100,000 per PDC bit as compared to roller-core bits.[5]
Diamond paste and slurry
[
edit
]
Diamond pastes are used for polishing materials that require a mirror finish. They are often used in metallurgical specimens, carbide dies, carbide seals, spectacle glass industry, and for polishing diamonds. Diamond paste is mainly used in industrial requirements for polishing and sharpening metal blades and other metal surfaces. The paste is not just to polish the metal blade but sharpen the cutting edge as well.
Diamond powder deposited through electroplating is used to make files (including nail files) and in small grinding applications.
Single point diamond turning (SPDT) utilizes a solid, flawless diamond as the cutting edge. The single crystalline diamond can be natural or synthetic, and is sharpened to the desired dimensions by mechanical grinding and polishing. The cutting edge of most diamond tools is sharp to tens of nanometers, making it very effective for cutting non-ferrous materials with high resolution. SPDT is a very accurate machining process, used to create finished aspherical and irregular optics without the need for further polishing after completion. The most accurate machine tool in the world, the LODTM, formerly at Lawrence Livermore National Laboratory, had a profile accuracy estimated at 28 nm, while most machines seek a roughness within that deviation.[6]
SPDT is used for optics, for flat surfaces where both surface finish and unusually high dimensional accuracy are required, and when lapping would be uneconomical or impractical.
Diamond saw blades
[
edit
]
For high-speed gas powered cut-off saws, walk-behind saws, handheld grinders, bridge saws, table saws, tile saws, and other types of saws.
If you want to learn more, please visit our website diamond cutting tools factory.
Diamond tipped grinding cups
[
edit
]
Typically used on hand grinders for grinding concrete or stone.
Diamond tipped core bit or holesaw
[
edit
]
Hollow steel tube with diamond tipped segments for drilling holes through concrete walls in the construction industry, porcelain tiles or granite worktops in the domestic industry, or also used for sample core extractions in the mining industry.
PCD tool insert
[
edit
]
Used in machine tools for machining ceramics and high speed aluminium.
PD tool insert
[
edit
]
Used in turning centers for optics and precision surfaces.
Polishing pads
[
edit
]
Pads with diamond crystals for polishing marble and other fine stone.
Diamond wire cutting
[
edit
]
Wire with diamond crystals for cutting.
Some of the features of Diamond Wire Cutting are:
Non-percussive, fumeless and quiet
Smooth cutting face
Unlimited cutting depth
Horizontal, vertical and angled cutting of circular openings up to 2500mm diameter
Plunge cutting facility which allows blind and rebated openings to be formed
Remote controlled operation for increased safety
Diamond saw chain
[
edit
]
For cutting stone, concrete and brick with a special chainsaw.
See also
[
edit
]
References
[
edit
]
You shall make a breastpiece of judgment, in skilled work. In the style of the ephod you shall make it—of gold, blue and purple and scarlet yarns, and fine twined linen shall you make it. It shall be square and doubled, a span its length and a span its breadth. You shall set in it four rows of stones. A row of sardius, topaz, and carbuncle shall be the first row and the second row an emerald, a sapphire, and a diamond. Exodus 28:15 – 28:18
This reference has caused people to believe that diamonds were known in biblical times. But the ‘diamond’ comes from the erroneous translation of the Hebrew yahalom and Greek adamas.
The early history of the diamond is shrouded in mystery. When the first diamonds started playing a role in the lives of humans is simply unknown. Looking at the available literature the same thing keeps popping up: accurately translating ancient texts is very difficult. Two words which often have been translated into diamond, the Hebrew יהלום (yahalom – derived from halam which means to beat) and the Greek αδάμας (adamas which means indomitable or invincible) have caused confusion.
When we read the old testament we encounter several diamonds but their existence is solely based on the translation of the Hebrew yahalom. The word was used to indicate an extremely hard mineral, that is certain, but assuming that it was actually referring to diamond is a modern thought. We know that diamond is the hardest substance on earth but was it known as the hardest in biblical times too?
Greek literature indicates the same issue. The use of the word adamas, for instance by Plato, has been seen as an indication of diamonds being known to the Greeks but in fact, there is zero proof that this was the case. The word adamas was probably used to describe gold, Metals (Non-Noble) and perhaps even corundum.
Early gemological historians didn’t have access to (translated) Sanskrit texts so one hardly ever reads anything on India’s own historical sources on the use of diamonds. When diamonds became a part of our lives is unclear but where they entered is completely certain: in India.
An old Indian work, named the Arthasastra, which can be dated back to the 4th century BC gives us the first proper insight in when diamonds were first used. By then diamonds were known, traded and even taxed in India. The existence of diamond experts is mentioned together with a classification of diamond. This implies a rather thorough knowledge of the subject, something which could lead to the belief that diamonds were in use for quite some time by then.
Diamonds were known to and worn by the Romans. They were highly prized as ring stones and a few rings containing uncut diamonds have survived and are now in the collection of The British Museum. Pliny writes about diamonds in his Naturalis Historia, calling them: ‘The substance that possesses the greatest value, not only among the precious stones but of all human possessions’. He doesn’t mention any fashioning of the stones at all. What he does note is the incredible hardness of diamonds and (probably without knowing) Pliny mentions its perfect cleavage:
These stones are tested upon the anvil, and will resist the blow to such an extent, as to make the iron rebound and the very anvil split asunder. Indeed its hardness is beyond all expression … When, by good fortune, this stone does happen to be broken, it divides into fragments so minute as to be almost imperceptible. These particles are held in great request by engravers, who enclose them in iron, and are enabled thereby, with the greatest facility, to cut the very hardest substances known.
Some of the quote above certainly sounds like diamonds are being discussed but Pliny mentions a few things which don’t add up. This must indicate that he confused some other minerals with diamonds. Herbert Tillander, who has written an excellent book on the history of diamond cutting, expresses his doubts about the Romans having access to perfect crystals; the Indian suppliers would certainly have kept the better stones for the native market.
Diamonds were believed to protect the owner from all kinds of mishap and, for a long time, it was believed that this divine crystal would lose its powers when it was in any other state than the natural one. Cutting diamonds was as much a taboo as it was difficult in the Ancient times. Tillander suggests that diamond cutting started with removing mineral matter off the faces of freshly mined crystals, which makes perfect sense. Whether controlled cleaving was being performed is unknown. This is such a rudimentary practice that there were no technical limitations preventing the ancient people to apply it to their off-shaped diamond rough but historical or archaeological proof of any early cleaving lacks completely.
After the decline of the Roman empire diamonds disappeared from European jewelry altogether. India was the only source of diamonds until the 18th century and the supply chain to Western Europe got disturbed by the lack of Roman merchants. The spread of Christianity had already subdued the popularity of the gem. The new religion condemned the superstitious attributes which had accompanied the stones. Contrary to the European situation, the gem retained its popularity in the Indian and Islamic world and it is in historic sources from these regions where interesting historical references are to be found.
The Ratnapariska by Bhudda Bhatta, an Indian text which, at least, dates back to the 6th century notes the following:
Wise men should not use a diamond with visible flaws as a gem; it can be used only for polishing of gems, and it is of little value.
Since polishing other gemstones with a full crystal isn’t feasible this text must have indicated the grounding up of bad quality diamonds in order to create diamond powder.
Our historical trip then takes us to the 10th century where Al-Biruni writes this:
…these people also say that it (the diamond) is the hardest amongst all precious stones and overcomes all other stones, yet the softest and least compact metal breaks it, that is, the lead which is wax like. …It (the lead) also pulverizes the diamond… When on grinding and pulverization its (the diamond’s) pieces get smaller the jewelers coat them with something that keeps the flies away.
Now, why is this so interesting? First, here we have reliable historical sources telling us that 6th-century Indian lapidary workers and 10th-century Islamic jewelers were grinding up diamonds in order to polish other stones. What is remarkable is that somewhere else in the same text Al-Biruni dismisses a stone from being a diamond because it’s crystal faces could be polished. This would imply that the polishing of diamonds with diamond dust wasn’t known yet by the 10th century.
Jack Ogden, a notable jewelry historian, reports to have seen Medieval Islamic jewelry that could be dated back to the 13th century which contains simple Table Cut diamonds. These would be the oldest known cut diamonds in existence. Ogden’s report coincides with historical literature. An Indian text named the Agastimata, which unfortunately hasn’t been accurately dated but is believed to be written shortly after the 13th century AD, teaches us the following:
The diamond cannot be cut by means of metals and gems of other species; but it also resists polishing, the diamond can only be polished by means of other diamonds.
European diamond cutting would have originated in Venice, shortly after 1330. This is indeed very likely since it was only after Venetian merchants started opening up the trade routes to the East that diamonds started trickling into Europe again. Whether cutting techniques were part of this new import to Europe isn’t clear but can be called plausible given the fact that both the practice of grinding poor quality diamonds to dust and the cleaving of diamonds were known by the men who were supplying the Venetians with diamonds: the Islamic merchants. Definite proof of where diamond cutting originated hasn’t been found yet, it could just as easily have been a European invention which backtracked the road the diamonds traveled.
Just as in Ancient times, perfectly shaped crystals would not have been reaching the West in any quantities. Their popularity in India would have caused the better samples to be preserved for the local market and the Islamic middle-men would certainly have picked the eyes out of the supply as well. Perhaps this is why Europeans started to cut diamonds? It is possible that the demand for perfect crystals and lack of such a supply triggered the start of diamond fashioning in Europe.
Technical limitations caused the first cutters to stick to what their rough allowed them to do. At first diamond cutting would have been nothing more than superficial polishing of the existing rough. The introduction of continuous rotary motion in craft tools in the 15th century enabled cutters to grind facets into diamonds with greater ease which expanded the possibilities. This triggered more creativity and a wider variety of cuts.
Following the Venetian re-opening of the East, the Dutch, Portuguese, Spanish and English naval explorations to all corners of the globe assured a new, and steady, influx of luxury goods into Europe. The Portuguese conquered the City of Goa in 1510, which they made the main diamond port of India. This enabled Europe’s diamond supply to grow considerably. Compared to the past, better rough would have been made available now that a direct line of supply was set up. It should be noted though that diamonds weren’t plentiful at all. Their status would have only risen from super rare to rare.
For more stone floor polishing padsinformation, please contact us. We will provide professional answers.