1 June 2010
Diamond Hard Surfaces Limited is a young company with its sights set on solving abrasive wear problems in applications where component failure has very costly consequences. The company has pioneered the development of a novel low-temperature carbon coating process that can significantly improve operating life for components in critical applications such as the oil and gas industry.
The company has successfully transitioned its technology out of the laboratory and has established its first full production facility in the UK at the Caswell Science & Technology Park in Towcester, Northamptonshire. This has been equipped with state-of-the-art processing equipment to offer a rapid coating service for a wide range of engineered components used in challenging environments. Once it has consolidated its business activities in the UK and Europe, Diamond Hard Surfaces hopes to expand its business and facilities in to the US and Asian markets.
Business activities are focused on the company’s Adm® low temperature coating technology that can lay down a coating of amorphous diamond on a wide range of materials in thicknesses up to and beyond 40 microns.This proprietary technology is a relatively low temperature process based on plasma-assisted chemical vapour deposition. It is a process that works at temperatures below 100oC, which means that even certain plastics such as PEEK can be coated with this hard, abrasive resistant thin layer of diamond-like carbon. The process delivers high energy to the carbon atoms in the plasma without the normally high temperatures of up to 1200oC required when laying down polycrystalline diamond, for example.
Smooth, yet hard coating
The main attributes of the Adm® coating says CEO Chris Walker is the unique combination of surface properties. This is a very conformal with excellent adhesion properties combined with extreme hardness and toughness. Chris Walker says that the technology offers a unique combination of hardness, low friction, wear resistance and abrasive resistance.
“We fill a space between conventional coatings usually 1800 Hv max, 5 microns thick max, 300oC coating temp and CVD diamond; 10000Hv, many microns, 800oC deposition temp. Our material is 4000 Hv, can coat to 40 plus microns and deposit at 100 oC.”
Fig.1: downhole bearings for the oil & gas industry
Chris Walker explains that its coating is an ‘end of the line process’ aimed at high added value, parts. The largest parts which have been coated to date are 1.2 m by 200mm have been processed at the company’s manufacturing plant.
Potential customers that can benefit most from technology are those where component lifetime is a problem and maintenance/cost of failure is expensive. In these applications, it is often the case that the cost of failure of a part is much higher than the component cost.
In targeted applications, Chris Walker says this adds up to “extended lifetime in mechanical, electronic and optical components.” That means a factor of 10 times improvement in lifetime under extreme conditions compared to other materials or up to 18 times improvement in abrasion resistance compared to HVOF tungsten carbide for example
Broad application areas
The company has identified a number of industries such as aerospace, defence, medicine, process and oil&gas where its coating has potential uses. Applications include mechanical Seal faces, industrial cutting applications, high-speed water pumps, down hole valves/mechanical components and metrology equipment.
One of the largest applications exploited by Diamond Hard Surfaces so far is mechanical sealing. For the oil & gas industry the coating has been applied to mechanical seal faces. Seals are critical components in many process applications and work on the principle of sealing the high pressure process side of the operation from the low pressure side, usually by means of 2 high speed rotating discs with a minimal and closely controlled intermediate gap.
Modern mechanical seals can rotate at speeds from 1200 RPM up to and beyond 60,000 RPM and protect equipment such as pumps and compressors. The high-speed rotating faces are usually either ceramic or hard metal materials such as Silicon carbide and Tungsten Carbide. When these faces meet during dry running conditions; at start up or due to process interruption, the faces come together and can fail in as little as 30 seconds potentially compromising the equipment they are
protecting.In this application, the coating provides protection where there is the risk of frictional damage in the case of interrupted flow of the liquid medium.
Fig 2: Mechanical sealing solution
“Our coating is used to protect these faces from failure in dry running conditions extending their life in critical operating conditions and thus giving the operator time to react to the changes in conditions before equipment is compromised,” says Sergey Alekandrov, Chief Technical Officer. The low friction, conformal hard surface coating minimises heat generation and friction caused in this sliding contact, dry running condition. “Typical applications include the pharmaceutical industry where seals and other equipment are steam cleaned between process runs,” he adds.
Another successful application for Diamond Hard Surfaces has been for industrial cutting. With the coating applied to a cutting edge used in machines for volume production of plastic sheet , the life of the steel blades were extended by 20 times using the new carbon coating compared to uncoated blades.
The material’s ultra hard properties make it ideal for critical applications in aerospace and defence for components which are exposed to the effects of erosion from sand and other particles. These are often found at the front of flying vehicles which operate in hostile environments.
Steady Growth Plans
With its new manufacturing facility and current marketing efforts, Chris Walker hopes that the company’s current modest turnover will grow to about £3 m within three to give years. “The market over the past 12-15 months has been hard for production sales, fortunately development has continued and allowed us to build a portfolio of new applications, now there are signs that the market is beginning to grow again and we are well positioned to take advantage of this. We have a lot of demand for solving customer issues and balancing resources is always challenging,” Chris points out.
About Diamond Hard Surfaces
Diamond Hard Surfaces was set up in 2005 when Sergey Alekandrov, the company’s current Chief Technical Editor, from the Kachatov Institute in Moscow approached Oxford Technology Management, which specializes in investing in high technology start-ups, with an idea for a low temperature, hard, abrasive resistant amorphous diamond (SP3) coating. Within two years a commercial process for the deposition of the extreme, diamond like amorphous carbon based material was developed at its laboratory facilities and patented. The company is currently backed by OT4 fund operated by Oxford Technology Management, Element Six Ventures SRL and a handful of angel investors.