The aim of the programme was to optimize several metallization processses of composite surfaces in order to improve their electrical and mechanical properties. These were 3 dry processes: silver and aluminium sputtering, chromium and silicon reactive sputtering, aluminium and zinc flame spraying, and 1 wet process: electroless plating of nickel before silver electrodeposition. A new surface activating process by Corona treatment has been evaluated as pretreatment for composite adhesive bonding. The studies are finished and the optimization of the metallization processes has been completed. Characterization test results allowed the appearance of fields of application for each process. Among them aluminium and silver sputtering, and chromium and silicon reactive sputtering are the more suitable to be industrially applied on composite surfaces. Aluminium and zinc thermal spraying can be used for repairs of metallization. Silver electrodeposition on electroless plated nickel is a process very difficult to apply on an industrial scale. Corona treatment needs further investigation to confirm its ability to improve composite bonding properties.
The use of composites materials in the aircraft industry allows weight saving and manufacturing cost benefits but their surface properties are insufficient to cover the electrical, mechanical and chemical specifications of aircraft structures.
In this programme :
1.Several metallization processes will be optimized to be industrially applied on composites surfaces in order to improve their electrical and mechanical properties :
- two dry processes : physical vapour deposition (sputtering) and thermal plasma spraying
- one wet process : electroless plating.
The deposited layers and coated systems properties will be studied to check that they meet the required specifications.
2. A new surface activating process "corona treatment" will be evaluated as a pretreatment for adhesive bonding in terms of adhesion properties processing cost and quality control equipment.
1100 AE Amsterdam