Fatigue behavior of SiC particulate reinforced spray-formed 7XXX series Al-alloys

This paper presents the fatigue results obtained in high strength spray-formed 7XXX series Al-alloys reinforced with the addition of silicon carbide particulate. This is one in a series of papers reporting on experimental studies completed to analyze the effects of processing and composition on numerous properties of these 7XXX series Al-alloys. In this study, testing was performed in tension on specimens with a constant amplitude axial fatigue cycle of R = −1.0. Test results were also compared with results available in the literature. The metal matrix composite materials displayed a large increase in fatigue strength in comparison to commercial ingot metallurgy 7075-T6 and T7 alloys. The enhanced fatigue performance of the spray formed alloys is attributed to low crack growth rates, resulting from inhomogeneous slip.