The effect of different profiling techniques on the fatigue performance of metallic membranes of AISI 301 and Inconel 718

Pure axial fatigue tests have been carried out on individual membrane links of metallic membrane flexible couplings manufactured by laser-beam machining, abrasive water-jet cutting, electro-discharge machining (EDM), EDM and shot peening, and by the traditional process of stamping. The two strip materials under investigation were AISI 301 in the half hard condition (20% cold reduction) and Inconel 718 in the solution-treated and aged condition. Only the fatigue performance of the EDM and shot-peened membranes was comparable to that of the traditional stamping process. Metallography, microhardness measurements and surface roughness measurements were carried out to assess any surface changes. The resulting fatigue life for each profiling technique was related to the surface roughness, residual stress and metallurgical changes.