纳米金属结构材料的韧化
Toughening of Nanostructured Metals
(a) schematic of the tensile bar sample of which the gauge section was processed by means of surface mechanical grinding treatment (SMGT)
(b, c) schematics of the cross-sectional microstructure of the gauge consisting of a gradient nano-grained layer (dark blue) and a deformed coarse grained layer (blue) on a coarse grained core (light blue)
(d) a typical cross-sectional SEM image of a SMGT Cu sample
(e) a cross-sectional bright-field TEM image of microstructures 3 mm below the treated surface (The arrow indicates the processing direction, and the inset shows the electron diffraction pattern)
(f) a transversal grain size distribution from TEM measurements in the top 5-mm-deep layer
(g) variation of average transversal grain (subgrain or cell) sizes along depth from the surface (Error bars represent the standard deviation of grain-size measurements)
