Diamond grinding wheels are a relatively recent product among grinding wheels, having been developed only after the discovery of synthetic materials. Synthetic diamonds were created as a result of research into synthetic materials, as was cubic boron nitride, or CBN. Synthetic diamonds are currently one of the toughest materials utilized in the manufacture of grinding wheels. Nickel and copper coatings on synthetic diamonds ensure that they survive longer. Diamond grinding wheels manufactured from synthetic diamonds are thus extremely durable, earning them the moniker "super abrasives." click here to know what the diamond wheel is.
Diamond grinding wheels come in a wide variety of forms, including flat disks, cups, cylinders, cones, and wheels with profiles carved into their edges, among others. The typical classifications for diamond and CBN grinding wheels include shape, grit size, concentration, and bond. The diamond grinding wheels' abrasive grit size is chosen based on the cutting material's hardness.
When the grinding wheel is created for use in tool room applications, grit sizes between 120 and 180 are used. For use in very fine and high-quality surface finishes, the finer grits (220 or more) are typically made to order. The amount of abrasive used depends on the purpose for which the wheel will be used. The application determines the number of diamonds on the grinding rim. A concentration of 75 to 125 is chosen for stock removal of hardened steel or tungsten carbide, but a concentration of 150 is chosen if the grinding wheel's contact surface with the material is very small.
The bond used to hold the abrasive grains together during the manufacturing process of a diamond grinding wheel is another crucial consideration. The main bond options available today are metal bonds, resin bonds, vitrified bonds, and electroplated, with resin being the most popular. Bonds used in grinding wheels have been improved over the years. Vitrified and metal bonds are generally more expensive and must be custom ordered. Electroplated wheels are commonly used in cut-off wheels and low-abrasive grinding applications such as plastics.
The hardness of a diamond grinding wheel is assigned by the manufacturer. This is accomplished by either allowing or restricting the fracture of the abrasive grains. When abrasives easily fracture, the wheel is said to have a soft bond. Because fracturing is limited in hard-bonded wheels, they can withstand greater forces. Soft wheels are typically used on easy-to-cut surfaces and have a shorter life. Hard wheels are used for finer surface finishes and last longer.
The spacing of the abrasive grains determines the structure of a diamond grinding wheel. There will be fewer grains in an open-structure wheel than in a closed structure. The numbers 1 to 15 represent the wheel structure, while the higher number represents the open structure. Diamonds have a hardness of nine to ten. The wheel structure will be denser if the number is lower. The abrasive is selected with the substance to be shaped in mind. A good abrasive will keep the edge sharp and cut in clean, straight lines. As a result, a well-structured diamond grinding wheel should be able to sharpen itself while shaping another material.
Friability is another factor to consider when creating a diamond grinding wheel. Abrasives are chosen based on their friability and the nature of the material to be ground. Although diamond is the hardest material, it reacts with steel when cut. Diamond grinding wheels are made differently for different industrial applications. Grinding wheels designed for tungsten electrode grinders must be industrial-grade, high-performance grinding wheels that can be used in the most demanding applications. They are available as handheld and bench-top tungsten sharpeners for tungsten electrodes and are typically used in heavy-duty applications. Although silicon carbide grinding wheels can be used to rough grind tungsten carbide, only diamond grinding wheels are suitable for finish grinding.
The highest quality diamonds are used in lapidary diamond grinding wheels to provide a longer grinding life and faster, clean cutting. When working with gemstones, industrial diamonds are bonded to the edge to achieve the desired results. The wheels can be made with either plastic or steel cores, though plastic cores are preferable for machine bearings. These grinding wheels are typically used for rough stone or glass grinding and have a longer grinding life.
Carbide comes in a variety of grades, and some of them can have an impact on the diamond grinding wheel, especially if the carbide contains a high cobalt content. The softer the carbide grade, the greater the wear and tear on the grinding wheel. The diamond grinding wheel should have a higher concentration of diamonds for successful performance on carbide, while wheels with low diamond concentrations should not be utilized on carbide. To save the grinding wheel, it is sometimes better to rough grind the material first and then finish it with a 400- or 500-grit fine-grit wheel. Nothing beats diamond grinding wheels with a good grit size and concentration for carbides, as diamond grinding wheels offer higher grinding quality, and the investment will more than pay for itself in terms of performance and longevity.
Diamond grinding wheels are not ideal for grinding steel because the grinding wheel wears away when it comes into contact with it during high-speed grinding. Diamond wheels are used on carbides, whereas CBN wheels are used on steel. However, there are times when it is necessary to grind both steel and carbide, and some manufacturers make a hybrid grinding wheel with a special grit for this type of work. Plated diamond wheels are used to cut nonmetals such as plastic, fiberglass, rubber, nylon, and other synthetic materials.