Tensile prestrain memory effect on subsequent cyclic behavior of FCC metallic materials presenting different dislocations slip modes

The forming process of metallic products generally implies steps of large plastic deformation. Understanding the "memory" of this prestrain history on subsequent fatigue properties is therefore an important industrial requirement as well as a challenging objective. Following this purpose, the cyclic behavior of Face Centered Cubic (FCC) metals was investigated after different tensile prestrains and compared with the cyclic stress strain responses of the virgin samples. In the past, dislocations slip character was clearly highlighted as a significant factor influencing prestrain memory and the different materials sensibilities to this phenomenon were discussed on the basis of their stacking fault energies. Nonetheless, the domain of memory occurrence and its evolution as a function of cross slip ease remain unclearly defined. This paper will provide some clues in this matter by drawing cartographies of memory effect in the case of pure copper (easy cross slip), nickel-chromium alloy (planar slip) and 316L stainless steel (mixed behavior) subjected to axial loading at room temperature. From these cartographies, the existence of threshold of prestrain necessary to induce memory and threshold of plastic strain amplitude capable to erase memory will be discussed. (C) 2015 Elsevier Ltd. All rights reserved.