Nanolayer cuts friction between moving parts

A unique, polymer-based surface treatment produces low roughness parts and hardens metal surfaces in a single mechanical process. The process, known as Fricso Super-Finishing (FSF), is a patent-pending mechanical lapping process that uses a unique polymer developed by Friction Control Solutions (Fricso). The firm was set up in 2003 and is headquartered in Detroit, with R&D facilities in Israel. There are 20 employees in all but the FSF process has been in development for nine years. An organic nanolayer bonds into the metal surface through chemical reaction, improving surface roughness average (Ra), mean roughness depth (Rz) amplitude and the Bearing Area Curve (BAC), while increasing surface hardness. Fricso’s super-finishing solution is not a coating but delivers coating-like performance at a fraction of the cost, time and maintenance required by traditional coating solutions. It improves cost-effectiveness of existing super-finishing processes, including the reduction of process time and the cost of tools. It can also reduce costs by using steel-on-steel pairs rather than using extensive coloured metals, for example. Lior Ben Tsur, vice president of marketing at Fricoo, told Eureka: “The technology actually originates from some Russian inventors, but we’ve developed it further and have patents pending globally on the technology. The polymer is developed by our own chemists and scientists. Around 60 field test trials are now underway with companies in the automotive industry, agriculture, heavy duty machinery, racing cars and hydraulics. “As far as orders are concerned, the early adopter has been the racing car sector but we are confident it is only a matter of time before the automotive sector and others follow,” says Tsur. The reason so many companies are looking at the technology is that Fricso-treated metal parts enjoy a significant reduction in their coefficient of friction (COF), enabling improved energy efficiency of engines. They also have high wear resistance and demonstrate excellent performance under extreme tribological conditions, in boundary and mixed lubrication regimes. Consultancy Frost & Sullivan awarded Fricso its Technology Innovation Award for 2006. As Tsur points out: “In the automotive industry, energy costs are rising but design engineers are still expected to reduce harmful emissions – while developing high performance engine components that have longer service lives.” To achieve this, many engine parts are treated with chrome or phosphated, but new environmental legislation is starting to limit this. The coatings themselves are also relatively costly, as they are generally batch-type subcontract work rather than an additional in-line process in the company’s own plant. “Our challenge was to develop some kind of surface treatment that could be applied by automotive companies during production of metal parts,” explains Tsur. FSF can be adapted by the customer to existing superfinishing or lapping machines. It can be applied to cylindrical parts, flat surfaces and a variety of metals. It is commercially viable for mass production or small quantities. Just as important, the technology uses no hazardous waste materials and produces no waste products. The technology has been applied successfully to a number of industries, particularly in automotive. For example, a hydraulic piston was protected against wear in severe working conditions of high pressure (more than 370 bar), while untreated parts suffered adhesive wear. Exhaust valve stems on ‘Big-Foot’ racing trucks is another application, in which Fricso reduced breakage of stems and wear, leading to improved service life. FSF reduced the coefficient of friction of chrome-coated rods (hardness Rc 74) and the peak height (Rpk) of shock absorbers by 50%, using the customer’s existing, centreless, through-feed super-finishing machine. Another customer has been comparing FSF, phosphate coatings and a baseline on its rocker shafts for engines. Fricso’s treatment proved the most cost effective solution, taking performance, reliability and cost into account. The technique also reduced the coefficient of friction by 25% on a spider for a customer’s CV joint, leading to a longer service life. All other alternatives tested by the customer had failed. Tsur told Eureka about another Fricso process, called Surface Engineering Treatment (SET). “It’s a two-stage process that combines surface texturing techniques, or ‘vibro-grooving’, and our own polymer lapping process.” Vibro-grooving creates tiny surface grooves, which act as lubricant reservoirs while funnelling out any metal debris that is created during sliding friction. “Lubricant from the grooves is forced onto the surface due to the increased pressure from the counterpart,” says Tsur. “The lubricant pockets are sustained through the beginning of operation and running-in periods.” In a recent test, SET enabled a customer to eliminate the bushings between a con-rod and piston pin. The treatment delivered piston pins that exceeded the run-in period and gained a significantly longer service life. SET is easily adaptable (it takes two to three weeks to apply it to existing production machinery), so could be used for mass-production applications and small batch orders. One major European automotive manufacturer wanted the technology on an exclusive licensing arrangement. “We resisted the temptation to sell to one customer, as we believe lots of companies should be taking advantage of our technology.” It is currently in talks with a leading UK drive chain manufacturer and has shown the technology to Boeing. Within automotive, interested parties include VW, Toyota, GM and Ford. Hydraulics company Bosch Rexroth has also shown a keen interest. Fricso is also looking at the medical implant sector where the process could be used to reduce friction in hip and knee joints. Friction Control Solutions Pointers FSF is a mechanical lapping process that cuts friction and hardens metal surfaces in a single operation An organic nanolayer bonds into the metal surface to Around 60 field trials are now in progress, with the automotive industry taking most interest in the technology