Article ID Journal Published Year Pages File Type
5205705 Polymer Testing 2016 4 Pages PDF
Abstract
Hardness of materials increases with decreasing indentation depth from macro-to nano-scales, which is known as the indentation size effect (ISE). This effect has been associated with indenter shape, frictional forces, dislocation models and other features. We show an anomalously high ISE for a 1-μm subsurface layer in the hybrid nanocomposites based on densely cross-linked Cyanate Ester Resins (CER) containing functionalized 3-D POSS or 2-D MMT nanoparticles (NP). This effect disappears after mechanical stripping of the surface layer. Energy dispersive X-ray (EDX) spectral analysis shows that this anomaly was caused by increased content of NP (Si and Al elements), by 2.5 times, in the 1-μm subsurface layer. The hardness of the 1-μm subsurface layer in these brittle nanocomposites is due to its peculiar composition, and must be taken into account when considering mechanical strength and frictional properties.
Related Topics
Physical Sciences and Engineering Chemistry Organic Chemistry
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