Intermetallic-reinforced aluminum matrix composites produced in situ by friction stir processing

Friction stir processing (FSP) is applied to produce intermetallic-reinforced aluminum matrix composites from elemental powder mixtures of Al–Cu and Al–Ti. The intermetallic phases are identified as Al2Cu and Al3Ti, which are formed in situ during FSP. The volume fraction of the intermetallic phases in the in situ composites may reach as high as ∼ 0.5. The composites produced by FSP are fully dense with high strength, and the composite strength increases with the reinforcement content.