So far in our look at new developments in the synthetic diamond industry, we have seen how their development has progressed over more than 100 years, and we’ve taken a look at some of the many techniques that can be used to synthesize diamonds in a laboratory. But while those of us in the industry are usually concerned mostly about how synthetics will affect the market for natural diamonds, the truth is that this is but a small fraction of what synthetic diamonds are used for. Let’s take a closer look at some of the current and prospective industrial applications for synthetic diamonds.
It is important to maintain a sense of context about the scale of synthetic diamond manufacturing. Natural diamond mining produces between 130-140 million carats of diamonds annually. Of that, about half is gem quality, suitable for use in jewelry. Contrast this with the output of synthetic diamonds, which is estimated to exceed 15 billion carats a year. China is by far the largest producer of synthetic diamond, and accounts for an estimated 90% of global production.
A relatively new but rapidly growing application for industrial diamonds is in cutting wire. Some analysts have estimated that by 2020, China could produce up to 9 billion meters of diamond cutting wire annually. Steel wire is coated in a resin, which is then impregnated with diamonds of different sizes, ranging from powder in the case of a very thin wire, to more than one-millimeter diameter diamonds in the case of thick industrial cable. Unlike traditional saws, which generally cut only in one direction, diamond wire can be used to cut rounded edges or other complex shapes. Typically, the wire is mounted onto a pulley system that pulls the wire around rapidly against the cutting surface. These machines tend to be very light, compact, and mobile, so they can easily be moved around a worksite, unlike large cutting blades, which are often very heavy. On a small scale, diamond cutting wire can be used for very fine cuts; for example, to manufacture surgical equipment and computer parts. Currently, the applications for diamond wire seem to be growing faster than production can supply.
Diamond speaker domes have been shown to produce outstanding sound quality in high-fidelity sound. In addition to diamond being the hardest natural substance, it is also the stiffest, as measured by Young’s material modulus. Vibration inside a speaker is the primary reason for why sound quality gets degraded between the speaker and your ears. Diamond can be accelerated very rapidly without any physical deformation in shape. Researchers are using CVD to build diamond speaker domes that are lighter than their aluminum counterparts, and as stiff as any natural substance. At the forefront of this research is De Beers’ Element 6, which is working in partnership with British speaker manufacturers Bowers & Wilkins to produce their diamond 800 series of speakers.
While the term ‘heat sink’ may not be something most people are familiar with, they surround us all almost everywhere we go. A heat sink is a type of cooling device inside many electronic and mechanical devices, like computers, semiconductors, and lasers. They are designed to extract heat away from high-energy components like CPUs or graphics cards. Most of them have a series of ‘walls’ that increase surface area to absorb heat, and a fan to push it out of the device. Aluminum is currently the most common material used, but engineers are now experimenting with diamond wafers. Monocrystalline synthetic diamond has the highest heat conductivity of any known substance, and is therefore the best material known to absorb the heat from within a device. Similarly, diamond wafers can be used for microchips, which would allow significantly more heat transfer than silicon, the current standard. Mass production of diamond microchip wafers could help to achieve the next quantum leap in computer processor power, and the development of artificial intelligence.
Ball bearings are another tool that exist without our knowledge in many devices that we use every day, such as cars, skateboards, and hard drives. They are so important to the functioning of vehicles, that in World War II, the Allied forces attacked a German ball bearing manufacturer to cripple their army. Ball bearings absorb a lot of punishment to do their jobs, including high heat and friction. The hardness, resistance to abrasion, and thermal conductivity of diamond makes it a perfect choice for use in ball bearings. Testing has shown that diamond bearings can outlast tungsten carbide by as much as eight times. The requirement to shape diamonds into perfect spheres is currently an impediment to wide scale commercial use of diamond ball bearings. However, industry is working on solutions to this problem, and you may soon find diamonds inside your cars wheels and engine.
Diamond lenses have been available in eyeglasses for years, but the high cost of development has kept them from becoming a mainstream product. Diamonds have a high index of light refraction, which is well suited to eyeglasses and contact lenses. Diamond eyeglasses can be built thinner and lighter than traditional lenses. This is especially useful for those with strong prescription eyewear, to avoid the “coke-bottle” look. Diamond lenses are also used for terahertz spectroscopy, which detects and controls properties of matter with electromagnetic fields. This has many applications in the medical field, including laser surgery, since a diamond lens allows for superior focusing of a laser beam. Even the space program is using the properties of diamond lenses to analyze the spectrum of electromagnetic radiation emanating from distant stars and galaxies.
Scratch- and friction-resistant coatings are another use for synthetic diamonds. A Motorola study from a few years ago noted that nearly a third of US smartphone users owned handsets with cracks in them, and that many would continue to use them even after cutting their fingers. Diamond coatings have the potential to reduce or outright eliminate this, and several companies are working with major cellphone makers to supply diamond-coated cellphone screens. They promise to be stronger than Corning Gorilla Glass, or even the sapphire crystal used in Apple watches. Rolls Royce recently unveiled a new version of its Ghost luxury sedan, which features paint made from 1,000 crushed diamonds. It may not be too far in the future when all car manufacturers are using diamond-based paints and enamels to make scratches on your car obsolete.
The truth is that the commercial uses for diamonds are immense, and industry continues to research new applications every day. Diamond is a unique mineral with physical properties not seen in any other material on Earth. We may have only scratched the surface of what will be possible in the future.
The views expressed here are solely those of the author in his private capacity. No one should act upon any opinion or information in this website without consulting a professional qualified adviser.
Diamond industrialist Ehud Arye Laniado is a man passionate about diamonds. From his early 20s in Africa and later in Belgium honing his expertise in forecasting the value of polished diamonds by examining rough diamonds by hand, till today four decades later, as chairman of his international diamond businesses spanning mining, exploration, rough and polished diamond valuation, trading, manufacturing, retail and consultancy services, Laniado has mastered both the miniscule details of evaluating and pricing individual rough diamonds and the entire structure of the diamond industry. Today, his global operations are at the forefront of the industry, recognised in diamond capitals from Mumbai to Tel Aviv and Hong Kong to New York.