A diamond blade is a saw blade which has diamonds fixed on the blade's base to use the diamonds to cut hard or abrasival materials. There are many types of diamond blades, and they have been applied in many industries, for example, construction industry to cut stone, concrete, asphalt, bricks, glass and ceramics, IT industry to cut semiconductor materials, and gem industry to cut gem stones including diamonds.
Types of diamond blade
Diamond blades can be categorized by their shape, use, and manufacturing method.
Types by shape
If categorized by their style, diamond blades are available in different types: circular saw blades, gang saw blades and band saw blades.
Circular diamond saw blades are commonly sighted and the most widely used. Most diamond blades are of this style.
A diamond gang saw blade is a long steel plate with diamond segments welded on it. Normally, a group (tens or even hundreds) of diamond gang saw blades are used together to saw raw stone blocks.
A diamond band saw blade is a flexible closed steel band with diamonds fixed (often via the electroplating method) on the teeth of one side of the band.
Types by use
If categorized by use, there are marble diamond blades, granite diamond blades, concrete diamond blades, asphalt diamond blades, general purpose diamond blades, masonry diamond blades, gem cutting diamond blades, etc.
Types by manufacturing method
There are many methods to attach diamonds onto the saw blade's base . A common method is sintering the mixture of diamonds and metal powders are formed to the blade's cutting edges -- diamond segments, and the produced diamond blades can be called sintered metal-bonded diamond blades. Other methods include electroplating, vacuum brazing, extruding and so on.
Electroplated diamond blade
Diamonds are electroplated onto the metal blade base. Electroplated diamond blades can be made to be very thin. The thickness of the blade can be tens of microns and can be used in precise cuttings.
Vacuum Brazed diamond blade
Synthetic diamond particles are welded to the outside edge of the circular saw blade via a vacuum brazing furnace. All of the diamond particles are on the exterior cutting edge of the blade, with no metal/diamond mixture. When using a vacuum brazed diamond blade you need not match the type of blade with the material being cut. Depending on the manufacturers recommended blade application, vacuum brazed blades will cut a wide variety of material ranging from concrete to masonry, materials like stone and brick, to steel, various irons, even plastic, tile, wood & glass. Always consult your blade manufacturer for a full list of cutting applications.
Smaller finer synthetic diamond grits will provide a smoother finish with no chipping on tile or burring on steel. Larger diamond grits will provide a faster cutting speed, but will likely cause chipping, burring or cracking of your material. Fire departments require blades to be made with a very large diamond grit, to tear through material fast, while a happy medium is required for the production industry.
Sintered metal-bonded diamond blades are the most common type. A blade of this type is composed of a steel core (the blade's base is steel plate, unlike diamond wire and diamond segments which are made by combining synthetic diamond crystals with powder metal and then sintering them. The diamond segments are also known as the "cutting teeth" of the blade.The steel core can vary in design. Some of them have spaces (known as gullets) between each segment to provide cooling and slurry removal, while others have a single continuous rim for smoother chip-free cutting. The type of core that can be used depends on the type of materials that the diamond blade is designed to cut.
Generally, there are three types of sintered metal-bonded diamond blades according to their manufacturing methods: wholly sintered diamond blades, silver brazed diamond blades and laser welded diamond blades.
A wholly sintered diamond blade is made by putting the steel core together with the diamonds and the metal bond materials into a mold and then sintering them in a sintering machine. So the diameter of wholly sintered diamond blades is not very big and normally is not bigger than 400 millimetres (16 in). Also because its participating in the sintering process, the steel core cannot be quenched, so the hardness and strength of the core is not very high, these types of diamond blades may deform in high-load and high-intensity cutting processes. Therefore, in some cases wholly sinter diamond blades' cutting efficiency cannot be very high.
Silver brazed diamond blades and laser welded diamond blades, however, do not have this problem. Because their diamond segments and steel core are treated separately. The steel core can be quenched and processed with other heat treatments, so its hardness and strength can be high, therefore the blade can be used in high-load and high-intensity cutting processes without deformation and high cutting efficiency can be gained.
Silver brazed diamond blades' diamond segments are brazed to the steel core using a silver solder. Silver brazed diamond blades can only be used in wet cuttings. Because if they are used in dry cuttings, the silver solder may melt under the high temperature generated in the dry cutting and the segments can break from the steel core and be extremely dangerous. While the laser melts and combines the metal of the diamond segment and the steel core creating a stronger weld, which can hold the segments even in high temperatures, so laser welded diamond blades can be used in DRY cutting applications and on high speed equipment.
Application of sintered metal-bonded diamond blade
A diamond blade does not actually cut. Instead, it grinds. They typically have rectangular teeth (segments) which contain diamond crystals embedded throughout the segment for grinding through very hard materials.
The bond is a term used for the softness or hardness of the powder metal being used to form the segments. The powdered metals hold the diamond in place. The bond controls the rate at which the diamond segments wear down allowing new diamonds to become exposed at the surface to continue grinding with a "sharp" edge. An important step in choosing a blade is to match the right bond to your specific material to be cut. Additional factors to consider are the type and power of the equipment to be used and the availability of water. The hardness of the bond is inversely related to the hardness of the material to be cut. Harder materials need a softer bonded segment to allow for continuous diamond exposure. Softer materials like asphalt or freshly poured concrete can use a harder segment to resist the increased wear that softer, abrasive materials create. In addition, the diamonds' grit (size), toughness and concentration should also match the nature of the material to be sawed. For example, when hard materials are cut, the size of the diamonds should be smaller, because smaller diamonds are more easily to cut into hard materials.
Apart from the nature of the material to be sawed, there are also some other important aspects that should be considered when you are choosing a diamond blade for your application. These aspects include the type (manufacturing method) of the blade, the availability of water in the cutting process, the horsepower of your saw machine, whether you need the blade to make lower noise, and so on. For example, if the horsepower of your saw machine is big, the bond of the diamond blade can be harder. This can extend the blade's lifespan. Because when the diamonds wear to an extent, the harder bond can still hold them. At this time, the blade becomes not so sharp, but your big-powered saw machine can still drive it and keep the necessary cutting efficiency.
Cutting with or without water
Diamond tools and blades work best when cutting wet. The water will prevent the blade from overheating, greatly reduce the amount of harmful dust created by cutting, and will remove the slurry from the cut. Diamond cannot withstand the forces involved at the elevated temperatures of dry cutting ceramic and abrasive materials, and will be subject to rapid tool wear and possible failure. Blade life is greatly extended by wet cutting. However, many blades are designed to operate either wet or dry.
When water cannot be used (electrical saws for example), measures should be taken so the operator does not inhale dust created by the process, which poses a very serious health risk. When doing dry cutting, the blade should be allowed to cool off periodically. Cooling can be increased by allowing the blade to spin freely out of the cut. This allows cool air to pass between the segments. Dry diamond cutting is dangerous for persons unfamiliar with the risks and process
B. Flexible Wet Polishing Pads
The faces of diamond polishing pads are designed with straight or curved slots, so they could be bent or distorted freely. They are backed with loop Velcro so they could be attached to any of backer pads very easy. They are used for fabrication of marble, granite, ceramic, and other hard and fragile material, as well as non-iron metal. They are widely used to polish stone, porcelain profiles, tile floors, all kinds of table-boards and stone sculptures.
Their working layer thickness is 2.2mm, 3mm or 4mm ,etc.
They are suitable for hand power machines with the power is 750W to 1500W that run up to a speed of 2000-10000 rpm.
Flexible diamond Polishing Pads attach to the Flexible Backer pads are used for grinding profiles or concave or convex surface as well as flat surface of stone, while attach to the rigid backer pads are perfect for grinding a flat or level surface like floor.
The process procedure: the operator sticks the flex pad on a backer pads and screw into Arbor of a grinding machine, and then brings to bear some pressure to the machine to grind stone surface for five times come-and-go, at the same time, the operator must infuses water into the backer pad continuously during the operation.
Then, the operator should change a finer pad. The grits of diamond pads are from #50, #100, #200, #400, #800, #1500, #3000, and #5000 to white/black buff in turn.According to the stone's quality and operator's experience, it could be cut down or save some positions of pads. White buff is used for light color stones and black buff for dark color stones. Each of grit is easily distinguished by different color of Velcro and the grit mark on the pad.
They are worked by water fed during the operation, so they are also called wet pads.
Measly water is needed from #1500, to #3000. For the buff, only less water is needed to wet the stone surface. This would make more friction resistance, and enough temperature on the surface of stone. Then stone surface is easily to be wiped off because of intenerate caused by momentary high temperature. But the stone couldn't be grinded by dry with too long time or it will result in burning or pigmentation. If burning appears, the worker must do work over again from #200 at least, and if the pigmentation appears, it must be from #400.
C. Diamond dry polishying pad
Some special floors (e.g. hotel's stone floorboard) are not allowed to work by wet, so the dry pads are used. Ordinarily, the dry diamond pads will not cause burning and pigmentation because of using the special resin to make the surface of pads intenerated and pealed off as well as to avoid too hot on the surface of stone.
They are excellent for marble polishing. They can be used by wet as well.