The influence of fibre surface properties on the mode of failure in carbon-fibre/epoxy composites

A series of mechanical tests have been performed on composites consisting o f high-strength carbon fibres in an amine-cured epoxy resin. A comparison h as been made between composites containing untreated, commercially treated (electrochemically), and plasma treated fibres. While both treatments impro ve interfacial adhesion, the manner in which the composite fails is totally different. In composites that contain electrochemically treated fibres fai lure is, in most cases, matrix dominated, whereas interfacial failure alway s occurs in samples made from plasma-treated fibres. This behaviour can be explained in terms of the nature of the fibre surface after each type of tr eatment. (C) 1998 Elsevier Science Ltd. All rights reserved.