Influence of processing route and reinforcement content on the creep fracture parameters of aluminium alloy metal matrix composites

An attempt to understand the rupture creep behavior of aluminum alloy metal matrix composites is made. Data from published investigations on the creep fracture of a variety of materials as well as new data on 6061Al-40 vol% SiCw composite have been analyzed. The analysis is made on the basis of previous studies conducted by these authors in which the relevance of the load partitioning phenomenon was manifested. The well-known phenomenological approach described by the Monkman-Grant equation has been employed. It is seen that the commonly used approximation of n′ = 1 (with n′ the Monkman-Grant exponent) is never satisfied. Rather, n′ < 1 is always obtained. A new form of this equation is proposed in order to understand the creep rupture mechanisms of these materials in greater depth.