The use of nanotechnology to improve the bulk and surface properties of steel for structural applications - Nanotechnology in Eco-efficient Construction - page 94

ultrafi ne layer, twinning layer, and compliant
coarse-grained layer from outer to inner of the stainless steel. This bio-
inspired design aims to benefi t from the synergy of multiple deformation
mechanisms and nano/micro-scale toughening. Figure 5.4 presents typical
TEM images of 304 SS after SMAT and its corresponding selected area
electron diffraction (SAED) patterns at four different depths (Chen et al. ,
2011).
Another advance in this fi eld deals with the use of surface-modifi ed
nano-Cu as effective lubrication additive (at 10 vol% in oil). It works by
'forming a chemical reaction fi lm on the steel' surfaces, thus improving their

nanocrystalline α ′ layer, α ′ - γ

g

a′

30

d = 10 nm

20

10

(a) (b)

100 nm

0

200 nm

0

20 40 60 80 100
Grain size (nm)

￿ ￿ ￿ ￿ ￿ ￿

(c) (d)

500 nm

5 5 5 μ μ μ m m m

5.4 Typical TEM images of 304 SS after SMAT and its corresponding
selected area electron diffraction (SAED) patterns at four different
depths: 5, 100, 250, and 400 m for (a)-(d) respectively. The lower

inset of (a) is the grain size distribution (Chen et al. , 2011). With kind
permission from Elsevier Science.

μ