Thermal cycling induced deformation and damage in Mo-fiber reinforced aluminum composites

Abstract

Unidirectional Mo-fiber reinforced aluminum composites were subjected to thermal cycling tests. The axial length of the composite increases with increasing thermal cycles. The Mo fibers remain intact and the interfacial reaction between fiber and matrix is insignificant after thermal cycling. To relax the internal stress built up in the composite due to differential thermal expansion of the composite constituents, cracks are developed along the fiber–matrix interface and propagate into the aluminum matrix. The formation of interfacial cracks causes reduced density with increasing thermal cycles. Thermally cycled specimens also show reduced tensile strength, which could be related to the presence of interfacial cracks in the composite.