Enhancing grain refinement in polycrystalline materials using surface mechanical attrition treatment at cryogenic temperatures

• DOI: 10.1016/j.scriptamat.2013.05.036
• Publication Date: 2013-06-05T06:00:29Z
• Authors: K.A. Darling; M.A. Tschopp; A.J. Roberts; J.P. Ligda; L.J. Kecskes
• Keywords: 02 engineering and technology; 0210 nano-technology

The surface mechanical attrition treatment (SMAT) process was applied to pure Cu at both cryogenic and room temperatures. The cryogenic SMAT process resulted in a 60% reduction of grain size in the polycrystalline microstructure compared to that at room temperature. The level of grain refinement is related to a transition in the dominant deformation mechanism during SMAT from a dislocation-mediated behavior at room temperature to a twinning/shear band-mediated behavior at cryogenic temperatures, which also helps to suppress thermally activated processes.