Cyclic stress–strain response and low-cycle fatigue damage in ultrafine grained copper

✍ Scribed by H.J. Maier; P. Gabor; I. Karaman

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 360 KB
• Volume: 410-411
• Category: Article
• ISSN: 0921-5093
• DOI: 10.1016/j.msea.2005.08.079

✦ Synopsis

We report on the fatigue behavior of ultrafine grained (UFG) copper obtained by equal channel angular extrusion (ECAE). Cyclic stress-strain response and fatigue life data were determined in fatigue tests conducted in the low-cycle fatigue (LCF) regime. The early stages of the fatigue process were examined in a scanning electron microscope equipped with a small-scale load frame that allowed for in situ fatigue observations.

The ECAE route 16E gives superior fatigue performances as it provides for stable cyclic stress-strain response and more homogeneous plastic deformation than routes that are composed of lower number of ECAE passes. Still, the in situ fatigue tests indicated that fatigue damage occurs on a very localized scale, and thus, additional strengthening mechanisms need to be exploited to obtain UFG materials that display enhanced microstructural stability.