Abstract Scope |
We fabricated core-shell SU-8 nanocomposite nanopillars via vapor-phase infiltration of nanoscale amorphous aluminum oxides, into their 50 nm deep surface region and performed microstructural and nanomechanical characterization as well as analytical and atomistic modeling to gain a fundamental insight into the ultrahigh modulus of resilience exhibited by these nanocomposites, which are orders of magnitude higher than most high-strength engineering materials. The results of experimental and numerical studies show that the ultrahigh modulus of resilience of our core-shell nanocomposites results from: the low aspect ratio of amorphous aluminum oxide nano-particulates; the particulate size being comparable to or slightly larger than the free volume of the composite matrix; and the extremely thin aluminum oxide interconnecting links emanating from nano-particulates. These unique microstructural features produce the unusual combination of low Young’s modulus and high yield strength, leading to the exceptionally high modulus of resilience as well as its weak dependence on strain rate. |