Low cycle fatigue strength of diffusion bonded joints of alumina dispersion-strengthened copper to stainless steel

It is proposed that the first wall and divertor components of ITER employ a lumina dispersion-strengthened copper (DS Cu) joined to austenitic stainles s steel. In this work, low cycle fatigue tests were performed on a direct d iffusion bonded joint, a diffusion bonded joint with a Au interlayer, stain less steel and DS Cu in order to investigate their fatigue strength and fra cture behavior. For the direct diffusion bonded joint, the fatigue strength in the small strain range was considerably lower than that of the DS Cu, w hile in the large strain range the fatigue strength was similar to that of the DS Cu. The low cycle fatigue strength of the Au interlayer joint increa sed compared with the direct diffusion bonded joint, and was the same as th at of the DS Cu. The strain distribution in joint specimens was not uniform , because the deformation stress was different between the 316 stainless st eel and the DS Cu. The fracture locations for the joint specimens varied de pending on their strain distribution. (C) 2000 Elsevier Science B.V. All ri ghts reserved.