Scientific Research Publishing

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...

Read  full  paper  at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53513#.VMcrZSzQrzE Author(s)     Shenglian Ren * , Chuanzhong Song , Jiahao Li Affiliation(s) School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, China . ABSTRACT Studies on the metamorphism and deformation conditions of rocks in the suture zone are good ways to discuss the orogenic process and mechanism. The microstructure and ultramicrostructure features of minerals are true embodiment of formation environment of the orogenic belt. Based on the study of microstructure, ultramicrostructure deformation characteristic and compositional zonation of garnets in garnets-mica schists in the Tongbai mountain, east section of the Shangdan fault zone, the results show that the three types of garnets have suffered various states of plastic deformation. The dynamic recrystallization of garnets is due to the subgrain gro...