High strain rate properties of a unidirectionally reinforced C/A1 metal matrix composite

Samples of a unidirectionally reinforced carbon/aluminum metal matrix composite, with fiber volume fractions up to 65%, have been subjected to compression testing at strain rates from quasi-static to ~ 1500 s−1. It was found that the ultimate strength was slightly strain rate sensitive and that it was considerably unproved if the fibers had been subjected to a surface treatment to promote fiber/matrix adhesion before consolidation of the composite. Samples tested parallel to the fiber failed by interfacial decohesion, followed by fiber buckling and kinking, while those tested perpendicular to the fibers failed by matrix shear. The results are interpreted in terms of present models for the compressive failure of composites and confirm the importance of fiber diameter, distribution, straightness, interfacial bond strength and alignment.