Influence of ceramic nanoparticles on fatigue life of Al 6061 prepared via ultrasonic aided rheo- squeeze casting process /

Abstract

The fatigue behaviour of Al 6061 along with its ceramic nanoparticles reinforced cermets fabricated through ultrasonic-aided rheo-squeeze casting technique are evaluated. The fatigue behaviour was studied under ambient and elevated temperature (250°C) conditions, and the effect of notches was also examined under same stress conditions. Al 6061 indicated service life of ~1.15 million cycles at low stress value which dropped to 15,470 cycles with increase in stress magnitude. Al cermet (ALST) shwocased enhanced = fatigue life up to ~35% for hybrid cermet with highest service life of 1.71 million cycles due to load transfer mechanism. In elevated temperature condition, life of Al 6061 dropped by 37%, whereas the reinforced cermets remained higher with ALST revealing high service life cycles. Further, notch indicated drop in fatigue life of Al and its cermets with cermets prevailing better than Al. The elevated temperature notch represented the lowest fatigue life owing to stress concentration as well as the coefficient of thermal expansion mismatch.