New aluminium composite

Citation

(1999), "New aluminium composite", Anti-Corrosion Methods and Materials, Vol. 46 No. 3. https://doi.org/10.1108/acmm.1999.12846cab.003

New aluminium composite

New aluminium composite

Keywords Aeroengines, Aluminium, Composites

A joint research project involving discontinuously reinforced aluminium (DRA) to reduce the cost and improve the performance of turbofan aircraft engine components has been completed by the US Air Force Wright Laboratory Materials Directorate, Wright-Patterson AFB, Ohio; the Title III Program office of the Manufacturing Technology Directorate; DWA Composite Specialties Inc., Chatsworth, California; and United Technologies Pratt & Whitney, USA.

DRA is a metal matrix composite consisting of an aluminium alloy reinforced with strong, stiff particles or fibres such as silicon carbide or alumina.

In stiffness- and weight-critical applications, DRA competes with polymer matrix composites, titanium, and aluminium alloys. The DRA material selected for fan exit guide vanes consists of a powder-based 6092 aluminium alloy reinforced with 17.5 vol. per cent silicon carbide particles.

This would replace the current polymer matrix composite (PMC), which has lower weight than aluminium and titanium vanes, but has high acquisition costs, erodes significantly in flight from weather, and has poor ballistics response to hazards such as large hail. Repairs to these PMC vanes are time-consuming and expensive.

The project reports that DRA provides the necessary ballistics response, as well as 33 per cent lower acquisition costs, significantly enhanced corrosion resistance, and reduced life cycle maintenance costs.

DRA fan exit guide vanes are expected to be retrofitted to Pratt & Whitney 4000 series engines, including those used in the US Air Force C-17 Globemaster III.

Further information from the Technology Information Center, Wright-Patterson Air Force Base, Ohio, USA. Tel: +1 937/255 6469.