Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Multilayer”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,279 records · Page 71
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Effects of three-dimensional Cu/Nb interfaces on strengthening and shear banding in nanoscale metallic multilayers

Manipulation of the atomic-scale structure of two-dimensional (2D) interfaces have been shown to provide nanocomposites with enhanced strength, deformability, and radiation damage resistance. In comparison with 2D interfaces, here we investigate the mechanical response of nanocomposites containing three-dimensional (3D) Cu/Nb interfaces consisting of a chemical/structural gradient separating pure Cu and Nb layers, through which the lattice mismatch between face-centered cubic Cu and body-centered cubic Nb is accommodated over a distance of several nanometers. Furthermore, it is demonstrated that 3D interfaces increase the yield and flow strength by 50% and 22%, respectively, over composites containing 2D interfaces at similar layer thicknesses. After 14% compressive strain, the onset of shear banding results in co-deformation of both Cu and Nb phases within and outside of the shear band. We conclude with a discussion of the role of interface structure in shear band formation and growth in 3D Cu/Nb.

3-dimensional interface↗
DOE OSTI2014

Room temperature reduction of multilayer graphene oxide film on a copper substrate: Penetration and participation of coper phase in redox reactions.

A self-reduction of graphene oxide (GO) at room temperature after prolonged storage on a copper substrate is evidenced by decrease of oxygen content and a dramatic, 6 orders in magnitude, increase in dc conductivity. Experiments revealed that the stored GO film contains copper hydroxide phase embedded in the reduced GO structure.

Voylov, Dmitry N↗
DOE OSTI2019

Bio-inspired nanocomposite by layer-by-layer coating of chitosan/hyaluronic acid multilayers on a hard nanocellulose-hydroxyapatite matrix

We report on a layer-by-layer technique on the hard CNCs/hydroxyapatite (HAP) matrix using biodegradable and biocompatible chitosan and hyaluronic acid (HA). Inspired by the mineralized collagen in human bone, the CNCs/HAP matrix was synthesized by a facile in situ HAP coating on the CNCs fibers. The chemical and crystalline structure of the CNCs/HAP matrix was investigated with FTIR, XRD, HRTEM, and SAED. The surface of the CNCs/HAP matrix was analyzed by AFM which showed a flat structure with a roughness of 23.12 nm, however, the surface roughness increased to 56.09 nm with the assembly of chitosan and HA. After the LBL assembly, the surface hydrophilicity of the CNCs/HAP films was improved. Furthermore, the CNCs/HAP matrix showed enhanced mechanical property than pure CNCs matrix. Although there is compromise in the mechanical property after the LBL assembly, it is anticipated its bioaffinity and biocompatibility will increase with the incoporation of chitosan and HA.

36 MATERIALS SCIENCE↗