The Electroforming—Filament Winding Process: A Method of Producing Metal Matrix Composites

Abstract

SummaryElectroforming coupled with filament winding can be used as a method of producing sophisticated metal matrix composites; this process has a close analogy to that already in use with plastic matrices. The main limitation of the Electroforming—Filament Winding Process (EFW) occurs when structures with a high winding angle are produced. In this case even at relatively low angles the level of porosity in the composites becomes high. The reasons for this and other parameters introducing porosity into the structure are examined, eg the effect of fibre size, composite growth rate, the use of non-conducting fibres and multi-filament tows. It has been found that a change in geometry is produced at the composite-electrolyte interface when any of the above variables is imposed upon the EFW process and this leads to localized alterations in electrodeposition growth behaviour. At high winding angles the resulting increase of porosity has been explained in terms of fibre crossover points which locally increase the radial fibre growth rate. This problem is due to the helical method of filament winding and it is suggested that it may be overcome by using a polar winding method.