Strength enhancement in thin-layered Al-Cu laminates

Abstract

Multilayered Al-Cu laminates were prepared by vapor deposition in vacuum onto NaCl substrates. The 25 °C stress-strain characteristics were measured for laminates having total thicknesses of 1.0 and 2.0 μm and layer thicknesses ranging from 20 to 1000 nm. For layer thicknesses ≲70 nm, the yield stress of the laminates is 4.2 times larger and the tensile fracture stress is 2.4–3.4 times larger than the values given by the rule of mixtures for Al and Cu. These strength increases are related to the basic physical properties of the metals and are in good agreement with Koehler’s theoretical predictions.

Wear and corrosion resistance of CrN/TiN superlattice coatings deposited by a combined deep oscillation magnetron sputtering and pulsed dc magnetron sputtering

“…Further increasing V s to -100 V, H and E were slightly increased to 37.3 GPa and 404 GPa, respectively. It can be inferred that the improvement in hardness of CrN/TiN superlattice coatings is attributed to well-defined interface, dense microstructure, increased compressive residual stress and decreased grain size [42][43][44][45].…”

A simple technique for determining yield strength of thin films

“…The strength levels reported for thin films are often higher than those for bulk specimens of the same material due to the existence of fewer defects in the thin specimen. [3][4][5] In some cases, the increase can be as large as a factor of 200. 6 Many experimental techniques have been developed to determine the yield strength, in particular, of thin films .7 These 89 experimental techniques inciude micro-tensile tests, ' nanoindentation, 1~ and micro-beam bending techniques.…”

Energy Saving Melting and Revert Reduction Technology (E-SMARRT): Development of Surface Engineered Coating Systems for Aluminum Pressure Die Casting Dies: Towards a 'Smart' Die Coating

“…the hindering of the dislocation movement, the Koehler's effect, and the coherency strain in the lattice mismatched materials [48,49]. In general, the dislocation blocking occurs when two layers in the multilayer have different shear moduli, and therefore different dislocation line energies.…”