Dynamic properties of metal matrix composites: a comparative study

Three distinctly different metal matrix composites have been tested at strain rates from quasi-static to ≈3000 s−1. It was found that the high strain rate response of each composite was determined primarily by (a) the response of the matrix in the absence of any reinforcement and (b) the damage formation and accumulation processes during deformation. High strain rate behavior of the short fiber composite was dominated by the matrix behavior at low strains but by fiber damage at high strains. The behavior of a whisker reinforced composite was dominated by the matrix properties at all strains. Re-loading tests produced increased fracture strains, indicating that adiabatic heating accelerates fracture of composites by permitting the development of local strain instabilities.