New solution for wear and friction problems opens door for pump industry revolution
New solution for wear and friction problems opens door for pump industry revolutionKeywords:Pumps, Wear, Friction
A breakthrough coating technology which offers solutions to problems not solved by any existing process is poised to revolutionise the worldwide pump industries, particularly where protection against abrasive materials is critical.
Known as Hardide and originally developed in Russia, the long life, low cost material – the composition of which is based on tungsten carbide – is able to coat all complex internal pump shapes with a unique low temperature gas phase deposition that provides a uniform super-hard finish. It is seen as a major boost in the fight against corrosion of expensive pumps, particularly those in hostile environments including oil, gas and chemical production. Two nickel-based alloys are often used in this sector, Monel and Inconel, and they can be easily coated with Hardide to increase their life expectancy by a factor of 100.
This will be particularly welcomed by offshore industries, for example, where salt and abrasive sand cause constant problems of downtime. Not only does the worn pump have to be pulled to the surface but potentially kilometers of tube as well. The impact that Hardide can make in this field is expected to be dramatic because its non-porous coating is also very inert and does not interact with other materials, making it an exciting breakthrough for its enhanced self-lubricating capabilities which reduce friction with the added strength to protect against wear and abrasion.
Accelerated wear tests performed in Russia showed that five pairs of piston sleeve hydraulic parts coated with 30 microns of Hardide outperformed case hardened piston sleeves by a factor of seven when subjected to the rigours of oil with diamond abrasive grit. Any other abrasive will be less hard than diamond and wear resistance is much more significant. Manufacturing and maintenance costs will thus be drastically reduced.
Hardide is being introduced to pump manufacturers worldwide following extensive research and development during the past 20 years in Russia and more recently in Oxford, UK, where the first application development centre in the West and only the second in the world – the other is in Moscow – has just been unveiled and from where samples can be obtained on request. Heading up the team at the new UK centre of excellence are two leading Russian scientists. Professor Yuri Lakhotkin, Technical Director of Hardide Ltd, is one of the world's leading authorities on chemical vapour deposition used in the Hardide process; while Dr Yuri Zhuk, Hardide Ltd's Managing Director, is not only a renowned academic but an expert in international technology transfer – and a prime mover in bringing Hardide's benefits to the West.
The revolutionary process is able to challenge all existing coating methods such as PVD, thermal or plasma spraying due to a unique combination of credentials including:
Super hardness (up to 3,500 HV).
An ultra low dry friction coefficient (from 0.1 to 0.2).
Chemical and corrosion resistant to water, salt and acids.
A wear factor of between 40 and 100 times less than case hardened steel– and up to ten times less than cemented carbide.
Outstanding erosion resistance, outperforming steel by a factor of 10 when subjected to a water/sand jet test at a speed of 10m/sec and by 100 when speed increased to 20 or 30m/sec.
Porosity of less than 0.04 percent.
Coating thickness with a variability range from five to 50 microns.
Nor does the Hardide technology produce one but a family of more than 20 coatings offering a variety of parameters to meet specific application requirements. All these coatings can be produced at one plant, while the composition and structure of each is controlled by the process conditions. Pumps are viewed as a key area for the process but its versatility means it is likely to be adopted by a wide range of industries. In the automotive sector, for example, the fact that Hardide provides a slippery low friction surface without lubrication will make it attractive to crankshaft bearing manufacturers among others, as will its extreme wearability make it ideal for components such as gudgeon pins and precision parts such as those found in fuel injection systems where there are very strict tolerance issues. Power steering boxes and suspension components are others in a seemingly endless list of potential applications in the automotive arena. The Hardide technology in theory at least may even pave the way for a new look at ceramic engines which have previously failed to make the grade because of brittleness limitations.
Hardide's composition, structure, coating method and applications have been protected by international patents covering 67 countries including the USA and Canada, the EU, Japan, Korea, Brazil and Mexico. "What we have with Hardide is not another coating but a solution to problems not solved by existing materials," says Graeme Hitchen, Business Development Manager. "So we want people to come to us and we'll see what we can do for them …"
For more information contact Graeme Hitchen. Tel: +44 (0) 1865 309677;E-mail: info@hardide.com
