LAUSR

Abstract Fatigue life of electric discharge machined and end milled samples of Inconel 718 alloy at high cycle fatigue mode was investigated. The objective of this work is to determine the influence of recast layer formed during the electric discharge machining on the fatigue life of Inconel 718. Data were generated in the fully reversed fatigue mode at ambient temperature using samples fabricated by following ASTM E606 standard. The specimens were machined on a spark electric discharge die sink machine. The specimens were subjected to fatigue, and the resulting fatigue lives and fracture morphology were compared with that of the end milled specimen. The surfaces of the specimens were examined under optical and scanning electron microscopes, and the roughness of the surfaces was measured using a standard surface profilometer. From the results of the investigation, it was concluded that the fatigue life of the samples fabricated by Spark Electric Discharge Machining decreased slightly when compared with that of the end milled sample. The results are explained using the data recorded on recast layer thickness, fracture mechanism observed because of the EDM process, and optical and scanning microscopy.