Lifetime behaviour of unidirectionally wire reinforced lightweight metal matrix composites

• The fatigue behaviour of a spring steel wire reinforced magnesium alloy is investigated.
• The reinforcement leads to an increase in lifetime.
• The occurring bridging effect after fatigue of the matrix can be quantified.
• The stress strain response leads to a derivation of a universal lifetime model.
• This simple lifetime prediction can be enlarged to other MMCs.

In the field of lightweight construction for transportation means, hybrid structures composed of high-strength and low-density materials exhibit a high application potential. The current work shows that a spring steel wire reinforcement content of 11.1 vol.% leads to a significant increase in lifetime of the magnesium alloy AZ31 under stress controlled fatigue loading. Based on the knowledge of the quasi-static behaviour of the single components and the fatigue behaviour of the single matrix material and on the understanding of mechanisms and mechanics of constituent deformation and damage evolution a new model is deduced from the quantitative strain response in order to predict the lifetime for different unidirectionally reinforced material systems.