Cyclic Deformation and Low Cycle Fatigue Behavior in a SiCw/6061Al Composite at Elevated Temperature

Abstract

The cyclic deformation and low cycle fatigue behavior of a SiC whisker reinforced 6061 aluminum alloy matrix composite were investigated at elevated temperatures with total strain controlled method. TEM and SEM were used to examine the microstructure and fracture surfaces of the specimens. The mechanical test results demonstrated that the composite materials maintained initial cyclic hardening at the elevated temperature. The fatigue resistance to cyclic strain of the composite was found to be inferior to that of the matrix material in the total strain controlled testing, while the composite material showed superior fatigue strength in the low cycle fatigue region within the temperature range in the present research. The fatigue failure of the composite is believed to be caused by a mechanism of nucleation, growth and coalescence of voids.