Abstract
The interface and thermal expansion behaviour of aluminium matrix composite (Al-3Mg) unidirectionally reinforced with continuous high modulus and high thermal conductivity carbon fibres Thornel K1100 were studied. The composite was prepared by gas pressure infiltration and was subjected to thermal cycling from room temperature to 350 °C.
It appeared that the current fibre – matrix – technology option effectively eliminated the undesired fibre matrix reaction. The Al₄C₃ carbide formation had been suppressed to that extent that their appearance in the structure was quite rare. However, TEM observations confirmed an amorphous layer at the fibre – matrix interface.
The thermal expansion of the composite is closely related to the expansion of fibres exhibiting negative coefficient of linear thermal expansion throughout the whole temperature range. This indicates that the interfacial bonding is relatively strong even without any excessive fibre – matrix reaction.

Key words
metal matrix composites (MMCs), Al/C interface, thermal expansion, CTE

Full text (437 KB)