DYNAMIC PROPERTIES AND ASYMMETRY OF TENSION AND COMPRESSURE OF METAL MATRIX COMPOSITES UNDER IMPACT LOADING

In this paper, the mechanical behaviors of 2124, Al-5Cu, Al-Li and 6061 alloys reinforced by silicon carbide particulate, together with the silicon carbide whisker reinforced 6061 Al alloy, were studied under quasi-static and impact loading conditions, by using the Split Hopkinson Tension / Compressure Bars and Instron universal testing machine. The effect of the strain rate on the UTS, hardening modulus, and failure strain was investigated. At the same time, the SEM observations of dynamic fracture surfaces of various MMC materials showed some distinguished failure characteristics, which determined the sensitivity of the strain rate of failure strain and the asymmetry of tension and pressure of MMC materials. Some new characteristics of asymmetry of mechanical behaviors of MMC materials under tension and compression loadings were also presented and explained in details in this paper, which can be considered as flags, to some degree, to determine the controlling mechanism of damage and failure of metal matrix composites under impact loading. The development of new constitutive laws about MMC materials under impact loadings should benefit from these experiment results and theoretical analysis.