Stress transfer along reinforced fibres of C f /Al composite during compaction

Abstract

Carbon fibre reinforced aluminium composite (C_f/Al) was successfully produced by a powder metallurgical (PM) method using low volume fraction (1%) reinforcement. It was impossible to produce a high (10%) fraction composite. This paper explains the difficulties in producing a high fraction fibre reinforced composite, especially when the carbon fibre (with large aspect ratio) modulus is superior to that of the aluminium powder particle. During compaction, stress (load) transfer is along the carbon fibre. On releasing the applied load, displaced fibres return to their original positions (elastic recovery). This causes a gap to appear between the fibre and the aluminium matrix, leading to a poor metallurgical bond. The disparity between the modulus of the carbon fibre and that of aluminium particles contributes to stress transfer along the reinforced fibre.