Additivity of reinforcing mechanisms during creep of metal matrix composites: Role of the microstructure and the processing route

During decades, great efforts have been devoted to understand and predict the creep behavior of discontinuously reinforced metal matrix composites, particularly aluminum alloy matrix materials. As a result of all these investigations, however, a confuse panorama of the precise role of the reinforcing particles on the enhanced creep response of these materials rules the present understanding. Here, an analysis of the reasons that have driven to this situation is made. Also, a simple and generalized framework of the relevant mechanisms required to understand this behavior is proposed. This view is based on previous work by these authors on 6061Al alloy, prepared by ingot and powder metallurgy, and 6061Al–15 vol.% SiCw composite, as well as a data analysis of published investigations aimed at clarifying the above situation. The additivity of the proposed contributions and the potential damage mechanism are discussed in the context of the processing route employed.