Figure 3
From: High strength metallic wood from nanostructured nickel inverse opal materials
(a) SEM images of inverse opal micropillars with 500 nm pores, before and after compression testing. The uncoated sample is 84% porous and the 19 nm nickel coated sample is 58% porous. Failure occurs in the [111] direction, parallel to the compression axis. Scale bars are 3 µm. (b) Engineering stress, σ*, versus engineering strain for micropillars under compression. The nickel sample is bulk electroplated nickel. (c) Strut yield strength, σy, as a function of strut diameter, d, for nickel inverse opal materials with 260, 500, and 930 nm pores. Blue data are nickel inverse opals measured with micropillar compression tests. Green data are nickel inverse opals measured with nanoindentation. Orange data are 500 nm pore nickel inverse opals coated with 19 and 33 nm of additional nickel. Shaded regions represent standard deviations. The fit line was only applied to nickel samples with no coatings.
