Effect of cyclic stress on the high temperature creep behavior of SICw/6061Al composite

Abstract

The static creep of Al-SiC system composites at high temperature has been systematically studied during the last decade because of their potential application at high temperatures. It is known that similar to oxide dispersion strengthened (ODS) alloys Al-SiC system composites also exhibit high values of creep activation energy and stress exponent. The stress exponent typically decreases with increasing temperature. Many structural components are subjected to repeated applications of stress at elevated temperatures under service conditions and several reports have addressed the high temperature fatigue properties of Al-SiC system composites, but the effect of cyclic stress on the high temperature creep behavior of this kind of materials has not been reported. This paper studied both static and cyclic creep of SiCw/6061Al composite at different high temperatures and attempted to determine how the cyclic stress and the unloading amount influence the creep behavior of the composite at different temperatures, such as the minimum creep rate, the apparent activation energy and the stress exponent.