The use of fibres to strengthen and stiffen materials is an art of nature that has existed long before the roaming age of dinosaurs, let alone that of mankind. Such a natural art is still with us to the present day, e.g. stems of trees and plants which are referred to as natural fibre composites. However, systematic development of fibre reinforced metals, or metal matrix composites, only began about 40 years ago [1]. Considerable interest was paid to metals reinforced with thin strong metal wires or glass fibres in the early 1960s. The problems of interface reaction and poor high-temperature strength of the fibres largely eliminated these composites from commercial consideration. Meanwhile, advances in aeroengine design and the use of cooling channels in turbine blades to reduce their effective operation temperature had, to some extent, diverted attention from metal matrix composites [2]. Only the past two decades have witnessed a substantial resurgence of research activity on metal matrix composites, due partly to the ever-demanding requirement for high-performance structural materials, particularly in the aerospace and automobile industries, and partly to the advent of high quality and/or new reinforcements [3, 4]. Various aluminium, magnesium and titanium alloys have been extensively tested as candidate matrix materials.