5 Common Questions About Industrial Diamonds For Grinding
1: What are industrial diamonds, and how are they used in grinding wheels?
Industrial diamonds can be either synthetic diamond or natural diamond and are specifically processed for industrial applications, rather than for jewelry.
Industrial diamonds are used in grinding wheels as an abrasive that removes material from a workpiece through friction and cutting. When the grinding wheel rotates against the workpiece, the diamond particles (abrasives) efficiently remove small particles of the workpiece – resulting in geometry, size, and finish desired.
Because diamond is the hardest known material, grinding wheels with diamond abrasives are commonly used in hard material applications that require high precision and accuracy such as in the aerospace, automotive, medical and semiconductor industries. CDT has experience working with grinding operations in all of these areas.
2: How are industrial diamonds manufactured?
Natural diamonds have been used for a long time in industrial grinding. They are mined from the earth and transported to a plant for processing. Through a system that includes x-ray machines and hand sorting, the gem quality diamonds are separated from industrial diamonds. These small, lower-quality stones, otherwise known as ‘boart,’ can be used in equipment such as grinding wheels, drill bits, and dressing tools.
Synthetic industrial diamonds used in grinding wheels can be made in one of two ways:
High-pressure and high-temperature (HPHT)
Chemical vapor deposition (CVD)
In the HPHT method, diamond-creating materials are put under high pressures and high temperatures to make it form into a diamond. In the CVD method, diamond-creating materials are put in a vacuum chamber where carbon gasses are then added to make it form into diamond.
Whether naturally or synthetically sourced, the industrial diamonds are then crushed, milled, cut, shaped, and polished to customizable sizes and shapes. Then, the particles are bonded together to form a grinding wheel or cutting tool, typically using metal, resin, vitrified materials or electroplated in a single layer onto a metallic substrate.
3: How do the properties of industrial diamonds affect the performance of grinding wheels?
Industrial diamonds are valued for their extreme hardness, wear resistance, and thermal conductivity. All of these impact the performance of a grinding wheel.
Extreme Hardness:
Diamonds are known for their extreme hardness because they are made up of carbon atoms that are held together in a cubic crystal lattice structure. You can think of it like a brick wall, where the precise arrangement and spacing of the bricks represents the arrangement of atoms in the cubic crystal structure. Like a brick wall, diamond is strong and stable, making it difficult to break or become deformed.
Because diamond is the hardest known material, it is not readily scratched by other materials. Instead, it does the scratching. Because of the high strength of the carbon bonds, Diamond has the best wear properties of all abrasives unless chemically attacked by materials that react with carbon.
This gives grinding wheels the ability to precisely cut through and remove material from other hard substances like ceramics, glass and non-iron-containing metals with very precise geometries and dimensional tolerances.
Wear Resistance:
A diamond's wear resistance refers to its ability to maintain sharp edges and cutting ability for longer, which results in longer-lasting grinding wheels that don’t need to be replaced as often.
Diamond particles can withstand high pressures generated during the grinding process – a crucial aspect of grinding that can cause other abrasive options to break down. Whereas the wear-resistant nature of a diamond abrasive maintains a durable, precise size and finish.
Thermal Conductivity:
Diamonds have the highest thermal conductivity of any known material, which is ideal for grinding due to the heat generated by the friction that occurs during the grinding process. Heat can cause abrasive particles in the wheel to become dull and less effective at cutting, as well as cause thermal damage to your workpiece.
Diamonds can conduct heat away from the grinding area more effectively than other abrasive materials. This keeps it cooler, protecting the material being ground from thermal damage and preventing the abrasive from becoming dull.
4: What are the advantages and disadvantages of using industrial diamonds in grinding wheels compared to other abrasive materials?
Advantages:
Diamond is the hardest known material due to it’s strong covalent bonds between carbon atoms and perfect crystal symmetry. Because Diamond is harder than all other materials it is the best choice for grinding and wear resistance. Other abrasives are softer than diamond and therefore do not last nearly as long. Secondly, Diamond also has the best thermal conductivity and therefore removes/dissipates most effectively the heat generated during grinding.
All of this makes diamond an advantageous choice as an abrasive because it will provide a longer-lasting durability, an improved precision, and a better quality finish.
Disadvantages:
Because of its high hardness, it also means that diamonds can’t be easily shaped or molded into different forms. Dressing of diamond wheels is done with Diamond tools, and with Diamond on Diamond, dresser life is low when compared with other abrasive types. Secondly, Diamond grinding wheels are not recommended when grinding ferrous metals as a chemical reaction between Carbon (Diamond) and the metal is possible and results in changes of the material properties of the metal and premature wear of the Diamond grinding wheels, both of which can be detrimental. Therefore, diamond is typically suggested for use in specialized applications for grinding of hard materials such as Ceramics, Carbides, and glasses.
5: What are the latest trends and advancements in industrial diamond technology for grinding wheels?
One of the latest trends in industrial diamonds is the increasing use of synthetic or man made diamonds. Diamonds that are grown in a lab are as real as diamonds mined from the earth. They are identical to natural diamonds in every way, except that they are created in a lab and the specific material properties of the Diamond can be tailored to specific applications..
As this process has gotten more efficient, man made diamonds can now be sourced cheaper and more readily than natural diamonds. Diamond grinding products are becoming more economically viable for a growing number of industries. CDT uses both natural and synthetic diamonds in its superabrasive products.
Another advancement in industrial diamond grinding technology is the creation of hybrid bond grinding wheels. Hybrid wheels combine different types of bond to adhere the abrasive material, such as diamond, to the grinding wheel and achieve superior grinding performance.
Traditionally, diamond grinding wheels use one of a handful of bonding agents to adhere the superabrasive material to the grinding wheel. Bonding options include:
Electroplating
Resin bond
Metal bond
Vitrified bond
Each of these bonding options have different characteristics which result in different pros and cons for the grinding process. You can learn more about the different bond types here.
By combining bonds, hybrid wheels can be tailored to the needs of specific grinding applications, resulting in higher efficiency and reduced costs. CDT specializes in cutting edge, customizable hybrid bonds using diamond abrasives to provide superior results for our customers. You can learn more about our hybrid bonds here.
Industrial diamonds are a crucial component in many grinding processes, and they continue to play a vital role in the manufacturing industry. Because of their ideal thermal conductivity, wear resistance, and hardness, the technology will continue to advance to make the most use out of this favorable material. It is safe to say that industrial diamonds are not going away anytime soon, and their importance in the manufacturing industry will only continue to grow from here!
If you are wondering if diamond grinding wheels or tools would be a good fit for your specific application, contact CDT for a free quote.