Dynamic properties and asymmetry of tension and compression of metal matrix composites under impact loading

The mechanical behaviors of 2124, Al-5Cu, Al-Li and 6061 alloys reinforced by silicon carbide particulates, together with 15%SiCw/6061 alloy, were stu died under the quasi-static and impact loading conditions, using the split Hopkinson tension/compression bars and Instron universal testing machine. T he effect of strain rate on the ultra tensile strength (UTS), the hardening modulus and the failure strain was investigated. At the same time, the SEM observations of dynamic fracture surfaces of various MMC materials showed some distinguished microstructures and patterns. Some new characteristics o f asymmetry of mechanical behaviors of MMCs under tension and compression l oading were also presented and explained in details, and they could be cons idered as marks to indicate, to some degree, the mechanism of controlling d amage and failure of MMCs under impact loading. The development of new cons titutive laws about MMCs under impact loading should benefit from these exp erimental results and theoretical analysis.