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 approximate to 3000 s(-1). It was f ound that the high strain rate response of each composite was determin ed primarily by (a) the response of the matrix in the absence of any r einforcement and (b) the damage formation and accumulation processes d uring deformation. High strain rate behavior of the short fiber compos ite was dominated by the matrix behavior at low strains but by fiber d amage at high strains. The behavior of a whisker reinforced composite was dominated by the matrix properties al all strains. Re-loading test s produced increased fracture strains, indicating that adiabatic heati ng accelerates fracture of composites by permitting the development of local strain instabilities. (C) 1998 Elsevier Science S.A.