Material advances are key to fast success

Many of the most striking technical advances to be found this year’s Autosport International Show were in materials. With constant pressure to improve fuel economy and reduce weight, many of the materials technologies being developed for sports and racing cars today are likely to be seen in increasing numbers of production cars within the next few years. Not all are wildly expensive. The annual budgets of Formula 1 teams may be measured in millions of pounds, but many of the performance cars on show were intended to be affordable. A striking track car launched at the show – the 40TR from GTM Cars – uses a glass fibre and aluminium chassis in a novel construction with a carbon fibre down force wing, yet costs only £7,695 as a kit or £15,995 factory-built. The power plant is only a Honda 2.0 type R engine but because of the car’s light weight, it gets from 0 to 60mph in “sub 4 seconds” and has a top speed of over 150mph. A Swedish company, Oxeon, represented at the show by Danish firm House of Composites, has invented a way of spreading out relatively inexpensive, thick tows of carbon fibre, to produce wide, flat, thin tapes that would normally require the use of more expensive, thin tows. Tows are defined in terms of the number of carbon filaments in each one. A 1K tow has 1,000 filaments and a 24K has 24,000 filaments. Oxeon CEO Andreas Josefsson says: “Traditionally, all weaving has depended on tow size. Manufacturers wanting to make thin structures had to use thin tows – but manufacturers want to make thick tows. We can use a 24K tow and produce a fabric that would normally require the use of 1K tows. We are increasing performance initially, but on large scale it would have an impact on costs.” The technique is the invention of Dr Nandan Khokar, who lives in Sweden, and came out of his PhD studies at Chalmers University in Gothenburg. The result of being able to use thin tapes is an ability to produce double thickness body shells that are exceptionally stiff per unit weight. Oxeon can produce tapes from 12K, 24K and 48K tows, and can produce carbon fabrics down to 100g/sq m in weight and up to 1500mm width. The company’s weaving process is described as “very gentle”, and allows processing of fibrous tapes of glass and aramid, as well as carbon, and can also be applied to relatively brittle materials such as boron and ceramic. Several vendors were offering a diamond-like carbon coating services for camshafts and other wearing components for very affordable sums. Bekaert (Sorevi) in Limoges in France cited a price of only 250 Euros to do a long camshaft. It calls the process ‘Cavidur’ and quotes wear factors on disk of around 50 x 10^-9 cubic mm/Nm as compared with 500 for titanium nitride, 700 for chromium nitride and 15,000 for steel. Still on the subject of coatings, Zircotec in Didcot offers zirconium oxide or aluminium oxide coatings on exhaust manifolds to protect adjacent heat sensitive components. It additionally claims that a 5% reduction in air intake temperature can raise horsepower by 1%, and a typical 30[deg]C drop can equate to 6%. The preferred process is to apply plasma sprayed zirconia – which is white – but sales manager Peter Whyman says that some customers prefer alumina, which is grey “for aesthetic reasons”. Applied to a motorcycle exhaust, the process additionally allows work on the bike very soon after it gets back to the pits. Another exotic material from aerospace, much favoured by engineers in motorsport if they can afford to use it, is titanium. Stephen Crownshaw of EOS Electro Optical Systems, says that in addition to being able to laser sinter cobalt chrome and 17-4 stainless steel, they will release titanium sintering by the second quarter of this year. “The machine we have has a sealed chamber so we can do it in an inert atmosphere,” he says. Sensors and electronics For those who suspect that their materials might be less than perfect, GE Inspection Technologies has developed the Phasor XS portable phased array ultrasonic detector. Unlike conventional ultrasonic flaw detectors, this uses the phased array to produce a 2D display, similar to those produced by medical scanners, on a 6.5 inch VGA screen on the front of the instrument. Tried on the GE stand, it could show up holes just over 1mm in diameter in an aluminium block. Eureka was told that it was equally effective in picking up small flaws in composites. Price is around £17,000. While not all workshops use such sensing systems to look for flaws in their fabrications, sensors to monitor what happens during races and the positions of components in “by wire” control systems have become the norm in all branches of motorsport. Reliability requirements are now coming close to those specified for use in aerospace. Variohm Eurosensor showed two new dual output sensors – one rotary and one linear – that are fully redundant, meaning that one of half of their systems can fail totally without affecting capability. The company’s linear DELPM50 and 70 linear potentiometers have separate power supplies and separate wiring – six wires in all – and are only 11.5mm in diameter. Applications are in sensing pedal, steering rack and suspension positions. The M 6090378A rotary sensor, however, takes redundancy one stage further by using two completely different technologies – a potentiometer and a “non contacting technology”. It has been specially developed for gearboxes. Penny + Giles, on the other hand, has for some time been into non-contact technologies for motorsport and was showing their SRH280 12-bit Hall effect rotary sensor, improving on the 10-bit sensor it launched last year, and a brand new ‘Contactless Linear Sensor’. The SRH280 has 0.088 deg measurement resolution and is 28mm in diameter. It is sealed to IP50 or IP68 and features four measurement ranges from 0 to 90[deg] and 0 to 360[deg] and a temperature error of less than 50ppm/[deg]C. It is available with analogue voltage or pulse width modulated digital signal output. The Contactless Linear ensor is a Hall effect device that works with a magnet that can be embedded in material up to 10.5mm below or 14mm above the base of the sensor. Measuring range is up to 28mm and linearity within {{plusminus}}0.5% at up to 25mm range. Pi Research has developed an inertial measurement unit – Pi IMU – that is small enough and light enough (it weighs 50g) to be worn by a motorcycle rider. With one on the rider and another on the bike, it has been used in Moto GP to monitor the difference between rider and bike lean angles. The Pi IMU is combines tri-axial gyroscopic and accelerometer data and a magnetic compass. Applications manager Roland Meister declined to give details of the gyroscope technology except to say that they were “solid state MEMS devices”. The company won The Technology and Innovation Award from the Motorsport Industry Association at a dinner on the opening night of the show. * The Autosport International Show, organised by Haymarket Exhibitions, was held at Birmingham NEC on 11-14 January.