Role of work hardening characteristics of matrix alloys in the strengthening of metal matrix composites

The strengthening of particulate reinforced metal-matrix composites is asso ciated with a high dislocation density in the matrix due to the difference in coefficient of thermal expansion between the reinforcement and the matri x. While this is valid, the role of work hardening characteristics of the m atrix alloys in strengthening of these composites is addressed in the prese nt paper. It is found that commercial purity aluminium which has the lowest work hardening rate exhibits the highest strength increment. This effect i s due to increased prismatic punching of dislocations. This relationship of decreasing work hardening rate associated with increasing prismatic punchi ng of dislocations in the order 7075, 2014, 7010, 2024, 6061 and commercial purity aluminium leading to increased strength increments is noted.