Abstract: The carbon fibre was electroplated continuously by a duplex coating of Ni prior to Cu,and the composite made of this carbon fibre together with Cu matrix has been investigated,the compatibility between carbon fibre and duplex coating and flexural strength,linear thermal expansion coefficient and electric resistivity of the composite have also been examined.Owing to the transformation of face-centred cubic Cu-Ni solid solution in the duplex coating under high temperatures,both the nodulizing shrinkage of Cu coating alone and the graphitization of carbon fibre accelerated by single Ni coating with a consequent loss of strength were im- proved.Because of the dissolving of minute carbon fibre in the interfacial Cu-Ni solid solu- tion,the bonding strength and flexural strength of the composite were significantly increased, and the length of carbon fibre pulled out on the fracture surface was obviously reduced.The interface of the composite seems to be of the dissolution bonding.

Key words: duplex coating, compatibility, composite, dissolution bonding interface