Protective coatings produced by thermal spraying processes comprise an area of great economic importance which cuts across most sectors of the European industry. The components protected include those suffering from corrosion and erosion in the power, petrochemical, gas, aerospace and construction industries.
At present the Arc Wire Spraying process which insure the highest deposition rate (up to 40 kg per hour) has poor oxide and porosity levels (cumulatively greater than 25%); besides the Vacuum Plasma Spray process which guarantees coatings with low oxide levels (less than 5%) is very expensive both in terms of the capital (of order 1 MECU) and operating costs (very low production rates). There is a need, therefore, of cost effective spraying processes which can insure a very high deposition rate along with a good coating quality.
The objective of this proposal is to develop wire and air plasma spraying processes with much higher quality (porosity less than 10% and oxides less than 5% for the air plasma spray and porosity and oxides less than 10% for arc wire) than present processes, with a potential of replacing vacuum plasma spraying in more demanding applications.
In order to reach this objective both an innovative shroud design and an "intelligent" control system will be developed. The shroud covering the outside of the spraying torch will provide shielding gases and avoid air entrainment to protect the spray stream from oxygen. The feed back control system will provide a self controlling or "intelligent" system, allowing to adjust the process parameters in order to maintain the torch and spray stream aligned on plasma and reduce stream divergence on wire systems.
The effectiveness of the processes will be demonstrated by coating real components such as valves, turbine blades and boiler tubes.
The Consortium brings together seven partners from five European countries, including five SME. The Consortium comprises an arc wire equipment manufacturer (Metallisation), a plasma process developer (Euromat), a company with considerable experience of plasma and arc wire systems (CA Technology), a developer of computer modeling software (VCIL), a coating producer and tribological expert (CISE), a power station arc wire spraying contractor as first end user (COMINT), a big power supplier as second end user (ENEL).
Funding SchemeCSC - Cost-sharing contracts
SO51 8BZ Romsey