DIAMOND WIRE DIES

One can hardly over-estimate the enormous importance of wire to our modern society. Millions of miles of wire are made each year for electrical and other uses. One factory alone makes a million and a half miles each month! Wire is made by drawing metal through a fine hole in a die. Softer metals can be drawn through a fine hole in a steel plate, harder metals through a hole in a carbide plate, but really hard metals or very fine wires produce so much relative wear on the die that only a diamond is hard enough and resistant enough to meet requirements. Wires of copper, steel, tungsten, and so on, can be drawn down to thickness of 1/5000 inch. For such fine wires 1 lb weight of metal can make 1000 miles of wire.

Tire point at issue is that in the rapid drawing of wire (and speed is necessary because of the huge mileages needed), the line die hole suffers wear unless the die is of very resistant material. Wear means, first, irregularity in shape, second, variability in strength of the wire and, finally, ultimate failure.

A diamond die is a high-quality (gem-quality) diamond through which a very carefully prepared fine hole has been drilled. This is by no means an easy operation. To begin with there is still some argument about which is the best direction, but we shall avoid this issue.
The diamond, preferably a rounded dodecahedron, since experience has proved these to be the strongest, is drilled to the shape.
Various drilling methods have been developed. The conventional way is to rotate a fine needle, which at the same time reciprocates up and down, using diamond grit on the tip. The method is slow and requires much skill. In modern methods the needle rotates at the exceptionally high speed of 100 000 rev/min, moving up and down meanwhile 200 times a second. Special ultrasonic vibrating machines are sometimes used.

Much faster drilling is obtained by using what is called an electrolytic method. The diamond is immersed in a liquid ad sparks passed to it from a fine platinum point. The spark drills through the diamond and is capable of producing an extremely fine very circular hole. Times have been reduced from two weeks for mechanical drilling to two hours for electric drilling. A good die is precious and some have been known to last several years of continuous use. If you want to buy diamond wedding bands visit this site.

The new light source, the laser, is the latest tool for drilling diamond. A laser is an optical device which produces an extremely powerful pulse of light energy for a short time, which may be one-hundredth part of a millionth of a second, As a rule, such a pulse produces a very irregular hole in a diamond, indeed it may shatter it completely (the impulse of the shock leads to a cleavage).

If a weakish laser beam is used, then a very fine (irregular) hole can be punched through the diamond and this can thon be used as a leader for mechanical drilling or electrolytic drilling. The method yet awaits development.

This section may be concluded by mention of the fact that diamonds drilled through have successfully been used as very resistant jets for a variety of corrosive liquids. Indeed, they have been used as jets in central heating systems in the U.S.A.

THE DIAMOND ROCK DRILL

The deep drilling of rock both for oil and other minerals is a basic part of the development of world-power economy. The strategic importance of oil need hardly be stressed, equally, without the diamond rock drill only surface or near-surface sources of oil would have been tapped, and modern civilization would have been very much the poorer as a result. Certainly, the handful of diamonds used in the deep drilling machinery are of strategic importance and are directly responsible for creation of a vast amount of wealth in the form of i recovered oil fuel.

All deep holes are drilled by using 3 stone diamond ring crown drills, and each year many many miles of exploratory holes are drilled in the search for minerals. It used to be stated in books dealing with the subject that the rotary diamond rock drill was invented in 1862 by R. Leschot of Switzerland. We have, however, discovered a much earlier illustration of rock drilling, with diamond, which is as follows. We found in the celebrated Encyclopaedia of Diderot, published in Paris in 1751. The text which accompanies this tells us that it represents a miner drilling a hole to be filled with gunpowder for blasting ore. We are told that the workman is using an iron bar with diamond octahedra set in the bottom, in rows, and that the tool is alternately raised and dropped, being meanwhile rotated. A hole about 2 feet long is drilled and then charged with gunpowder.

This is certainly a primitive diamond rock drill, and from this early kind there have now evolved both thin-walled diamond bits for drilling masonry and also massive bits for driving deep into rock in the search for oil.

The diamond bits for mining and civil engineering are essentially variants (and there are very many variants) of the arrangement. Individual diamonds are fixed in the 'crown' of a massive hollow metal cylinder. The crown may be segmented, with diamonds in each separate segment. As the drill goes down, a ‘core’ is forced through the central hollow tube and this gives the geologist valuable information about the rock section.

There is tremendous variety both in the shape of crown and also in the size and number of diamonds. Equally, there are various methods of encasing the diamonds. A crown may be 1 inch across with four diamonds each of ½-carat size, or it may be 14 inches across with numerous diamonds each of 5-carat size. Many drill crowns can consist of several hundred small diamonds, and some experimental crowns have used bonded arrangements of coarse grit.

In practice, diamonds are torn out and lost, and some drill heads are built of separate segments which can be replaced as the units are damaged.
For drilling short distances in rock or for drilling masonry in buildings, it is common practice to use drill bits with impregnated grit in the tip instead of single diamonds. If you want to buy diamond wedding bands visit this site.

DIAMOND SAWS

Sawing hard materials by means of diamond saws has become an important industry. At first, diamond saws were made by fastening individual diamonds round the rim of a wheel, or by forcing them into the edge of a long blade (gang-saw blade). There has of late been a considerable change in approach, and the majority of saws now made incorporate a thin layer of bonded diamond round the edge. A typical saw is shown schematically in which the bonded diamond region is shown shaded. Such wheels are made over an extremely wide range of sizes. Sizes of disc can vary from wheels a few inches across to wheels 8 feet in diameter! The large sizes can cost over £1500.

Diamond-bonded saws are used extensively in the building industry. Cement slabs can be cut to shape, porcelain, bricks, tiles, and so on, are easily shaped accurately also. The machines are now extensively used in connection with cutting stone for marble slabs for buildings or monuments, and especially for production of granite blocks. Large blocks are also reduced rapidly by the use of multiple blade-reciprocating saws. One advanced machine handles a cubic block of side about 10 feet, and has 40 blades cutting out blocks simultaneously. The saw blade edges themselves are about 1 inch wide, consisting of bonded diamond. Speed of cut is rapid and big blocks are quickly reduced.

Rotary saws have been found useful for making anti-skid ruts in concrete roads and aerodrome runways and have been brought to stone bridges and so on for cutting out sections on the spot to facilitate repair work. Check also diamond stud earrings.

A notable advance in speed of surfacing of roads and run-ways has resulted from the use of mobile saws and smoothing machines. These can rapidly traverse extensive stretches of motorway or aeroplane runways. Multiple blades are designed to cut long narrow ruts across a road, thereby producing an excellent anti-skid surface. The concrete surface is much too hard to be sawn by anything other than a diamond saw.

Diamond saws are extensively used in the furnace refractory industry, for materials such as heated alumina are very hard, and there is no other way of handling refractories. A high-speed rotary saw cuts very rapidly through a thick block of class and is therefore of considerable value as a time-saver in the optical glass industry. The blades have to travel fast, cutting edges needing to move at least at 100 feet per second. Adequate water flow on the blade during cutting is an essential. The type of bond and the grade of grit must be carefully adapted to each specific objective. A considerable number of difficult constructional problems have been solved by the use of diamond saws. One method uses a disc saw with corrugated i-edge, impregnated with diamond grit. This assists the water coolant flow, an essential part of diamond-sawing technique. Blades like this have found valuable application for rock cutting, glass cutting, shaping of abrasive material like asbestos hoard, and so on.

Diamond saws are used for facing bricks, surfacing stone slabs, and a host of other operations. Their use is not exactly strategic in that they are replaceable by other methods, but I they are enormously faster in functioning than old conventional techniques. The preparation of a big aerial runway with anti¬skid ruts would be an impossibly slow task without a high-speed rotary diamond saw.

Diamond Tools

Tools of all shapes and sizes are available, and manufacturers will supply data sheets about operational speeds and forces, and so on. Economy is high. For example, when tests were carried out on comparative lives of cutting tools made of steel, of sintered carbide and of diamond, in the manufacture of a bronze engine part, the steel failed after 1000 components, the carbide after 4000, but the diamond lasted up to 25 000. In terms of cost of tools the diamond turned out cheapest in the end, despite the fact that weight for weight diamonds costs 25 000 times as much as silicon carbide.

One enormous attraction in the use of diamond engagement rings for producing fine silky smooth finishes lies in the uniformity of the product right up to the end of life of the tool edge. Nowadays some special fine-grain, diamond-bonded wheels have succeeded also in producing very smooth mirror finishes on components. Such finishes are in high demand. It is possible to polish diamond itself with a bonded wheel. It is far faster than the traditional scaife. Unfortunately, a diamond polished in this way always shows chipped edges, so that the bonded scaife is not very popular with the gemstone polisher.

Superfine finish produced by specially shaped lathe-cutting diamonds is exploited in many industries, of which but a small selection include aluminium engine pistons, bronze bushings, calculating machines, lens mounts for cameras, components of microscopes, precision meters, Perspex components, manufacture of wedding rings, the components on watch faces, watch balance-wheels, and so on.

Diamond Tools

Correctly shaped diamonds can be gripped in a steel shank and used as lathe-cutting tools. They have four attractions, namely (a) they are so hard that they can attack the hardest of modern alloys, (b) they retain their sharp edges for very long periods of intensive use, (c) they are capable of producing superfine finishes, (d) they can attack all sorts of 'difficult' objects which give ragged results with conventional steel- or carbide-tipped tools. Diamond lathe-cutting tools are surpris¬ingly ubiquitous in the range of materials they can attack. One can turn and drill, on the one hand, soft metals like aluminium, silver and gold, and on the other, hard steels and carbides. Strangely enough they are admirable for soft rubber, such as that for the production of rollers for typewriters or printing machines, they are used for the turning of plastics, both soft and hard, and even for the processing of compressed paper rolls. Also check custom wedding bands. They are used extensively in the jewel trade, for turning watch parts and for smooth mirror-finishes on gold and silver. Equally, they are used widely in the automobile industry and can produce soft silky finishes on complicated alloys such as Babbitt metals, used for bearings.

It is necessary to set the cutting tool in correct orientation to present a hard edge and avoid cleavage direction, and this the manufacturer must do, yet the operative needs to use care. A damaged or blunted diamond (incorrect use. can chip edges) can be re-polished (by skilled diamond polishers only, of course) so is by no means a total loss. Lathe-cutting diamonds can be fastened into steel shanks by 70.