Interactions between non-screw lattice dislocations and coherent twin boundaries in face-centered cu.pdf

Available online at /locate/actamat Acta Materialia 56 (2008) 1126–1135Interactions between non-screw lattice dislocations and coherent twin boundaries in face-centered cubic metals Z.-H. Jin a,b,*, P. Gumbsch c, K. Albe d, E. Ma e, K. Lu f, H. Gleiter a, H. Hahn a aForschungszentrum Karlsruhe, Institut fu?r Nanotechnologie, Karlsruhe 76021, Germany bSchool of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China c Institut fu?r Zuverla?ssigkeit von Bauteilen und Systemen (IZBS), Universita?t Karlsruhe, 76131 Karlsruhe, Germany d Institut fu?r Materialwissenschaft, Technische Universita?t Darmstadt, 64287 Darmstadt, Germany eDepartment of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA fShenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China Received 23 February 2007; received in revised form 7 November 2007; accepted 8 November 2007 Available online 18 January 2008Abstract In a first report [Jin ZH, Gumbsch P, Ma E, Albe K, Lu K, Hahn H, et al. Scripta Mater 2006;54:1163], interactions between screw dislocation and coherent twin boundary (CTB) were studied via molecular dynamics simulations for three face-centered cubic (fcc) met- als, Cu, Ni and Al. To complement those preliminary results, purely stress-driven interactions between 60 non-screw lattice dislocation and CTB are considered in this paper. Depending on the material and the applied strain, slip has been observed to interact with the boundary in different ways. If a 60 dislocation is forced by an external stress into a CTB, it dissociates into different partial dislocations gliding into the twin as well as along the twin boundary. A sessile dislocation lock may be generated at the CTB if the transited slip is incomplete. The details of the interaction are controlled by the material-dependent energy barriers for the formation of Shockley partial dislocation