Mechanical behaviour and microstructural evolution of constrained groove pressed nickel sheets

作者：Kumar S S Satheesh^*; Raghu T

来源：Journal of Materials Processing Technology, 2013, 213(2): 214-220.

DOI：10.1016/j.jmatprotec.2012.09.012

• Mechanical behaviour
• Constrained groove pressing
• X-ray diffraction
• Grain refinement

Pure nickel sheets are subjected to severe plastic deformation by constrained groove pressing technique at room temperature thereby imparting an effective plastic strain of 3.48. The evolution of mechanical behaviour with increasing number of passes revealed intensive increase in strength properties after first pass; however marginal increase is observed subsequently. Gain in ductility which is attributed to dislocation recovery is observed after third pass along with marginal drop in strength. Microstructural evolution during groove pressing of sheets is characterized by X-ray diffraction profile analysis using Williamson-Hall method. Besides the observation of strong shear texture in constrained groove pressed sheets, improvement in strain isotropy with increased straining is revealed from Williamson-Hall plots. The sub-grain/cell size estimated by analysing the diffraction profile of deformed sheets is found to be similar to 1390 nm after processing up to three passes. Low grain refinement efficiency observed in this process compared to other severe plastic deformation techniques at similar strain conditions is explained by the deformation characteristics and loading behaviour experienced by the sheets during constrained groove pressing.

• 出版日期2013-2