The Wallwork Group, metal coating and heat treatment specialists, is to showcase at The Farnborough Airshow innovative processes to extend the service life and improve in-flight performance of critical aerospace components. The developments acknowledge the pressures to improve environmental performance of aircraft because of cost and environmental challenges. The company has developed treatments that will achieve substantial in-flight fuel savings and to reduce life-time costs for operators.
A family of multi-layer coatings based on titanium, chromium, chromium/aluminium or carbon/metal carbide, Nitron Flight has many aerospace applications. These include aircraft landing gear, engine bearings, high temperature engine seals and engine compressor blades.
For example, a major maintenance overhaul and repair contractor is deploying the chromium based coating on compressor blades, with remarkable results. They have proven fuel savings of $48,000 per year, reduced CO2 emissions by around 290 tonnes and enable compressor blades to retain their optimum aerofoil profile. The latter point is significant since it results in an extended interval between overhaul and fuel savings being maintained into the operation cycle.
Nitron O is another radical innovation. This titanium or chromium nitride based duplex coating improves the surface finish of titanium bearings enabling them to withstand higher loads and remain lubricious. Titanium is increasingly used as a light weight alternative to steel in aerospace for its strength and fatigue resistance. Unfortunately, the coefficient of friction of titanium and the propensity for metal to metal adhesion in some circumstances undermines these advantages. These limitations are overcome by Nitron O duplex coating.
The titanium surface is first hardened using a plasma based process to create deep and hard nitrided cases in the titanium alloy. Within the same process cycle the secondary nitride layer is then applied by physical vapour deposition (PVD) to create a surface that has steel-like properties, making it both lubricious and resilient under load.
Wallwork sister company, Tecvac, provides a full range of surface improvements based on carbon – from graphite coatings that are highly lubricious to diamond coating with extreme abrasion resistance. Diamond coating is particularly applicable to tools used in the drilling and cutting of aerospace composites. Conventionally hardened tools produce ragged edged cuts causing secondary damage and weakening of the material, while diamond coated tools cut cleanly.
In addition to their advanced coatings and treatments, Wallwork operate traditional vacuum, sealed quench and salt heat treatment processes. The company has extended their capability into non-ferrous heat treatment with a new aluminium furnace. This will permit the hardening of many aluminium aerospace components to improve their inflight performance, extend service life and operator margins and efficiency.
Contact, Simeon Collins, Sales Director
Tel. +44 (0)161 797 9111 Fax. +44 (0)161 763 1861
Wallwork Heat Treatment Ltd, Lord Street, Bury, Greater Manchester, BL9 0RE
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