The industrial application of lightmetals enhances the efficiencyofmachines and reduces energy consumption. Light metal alloys based on aluminium and magnesium have low elastic modulus, high coefficient of thermal expansion and low wear resistance compared with steel. However, these alloys reinforced with ceramic fibres or particulates have high elastic modulus and low coefficient of thermal expansion due to the properties of the reinforcement. Metal matrix composites are hard to machine and their production costs are high, and hence the number of commercialized metal matrix composite products is not large. Inaddition, recyclingofmetalmatrix composites hasbecomean important issue. Industrial uses of metal matrix composites are discussed in chapters 1-4.