Movement of Dislocations in the Sub-Surface of a Polycrystalline Metal by Cavitation Peening Observed by Transmission Electron Microscopy
Read full paper at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53714#.VNBuHSzQrzE Author(s) Osamu Takakuwa 1 , Akihiko Chiba 2 , Hitoshi Soyama 1 Affiliation(s) 1 Department of Nanomechanics, Graduate School of Engineering, Tohoku University, Sendai, Japan . 2 Institute for Materials Research, Tohoku University, Sendai, Japan . ABSTRACT The impact produced when cavitation bubbles collapse can be utilized to modify surfaces in the same way as shot peening and it is called cavitation peening (CP). CP is one of a number of surface modification techniques used to improve the fatigue strength of metallic materials by introducing compressive residual stress. Although it has been shown by an X-ray diffraction method that CP decreases the micro-strain related to dislocations in the sub-surface of a polycrystalline material, the mechanism for this decrease is unclear. In this paper, the movement of dislocations b...