https://zenodo.org/record/1258680/files/article.pdf

The influences of temperature and microstructure on the tensile properties of a CoCrFeMnNi high-entropy alloy

Alloying has long been used to confer desirable properties to materials. Typically, it involves the addition of relatively small amounts of secondary elements to a primary element. For the past decade and a half, however, a new alloying strategy that involves the combination of multiple principal elements in high concentrations to create new materials called high-entropy alloys has been in vogue. The multi-dimensional compositional space that can be tackled with this approach is practically limitless, and only tiny regions have been investigated so far. Nevertheless, a few high-entropy alloys have already been shown to possess exceptional properties, exceeding those of conventional alloys, and other outstanding high-entropy alloys are likely to be discovered in the future. Here, we review recent progress in understanding the salient features of high-entropy alloys. Model alloys whose behaviour has been carefully investigated are highlighted and their fundamental properties and underlying elementary mechanisms discussed. We also address the vast compositional space that remains to be explored and outline fruitful ways to identify regions within this space where high-entropy alloys with potentially interesting properties may be lurking. High-entropy alloys have greatly expanded the compositional space for alloy design. In this Review, the authors discuss model high-entropy alloys with interesting properties, the physical mechanisms responsible for their behaviour and fruitful ways to probe and discover new materials in the vast compositional space that remains to be explored.

High-entropy alloys

The discovery of uniform deposition of high-quality single layered graphene on copper has generated significant interest. That interest has been translated into rapid progress in terms of large area deposition of thin films via transfer onto plastic and glass substrates. The opto-electronic properties of the graphene thin films reveal that they are of very high quality with transmittance and conductance values of >90% and 30Ω/sq, both are comparable to the current state-of-the-art indium tin oxide transparent conductor. In this Feature Article, we provide a detailed and up to date description of the literature on the subject as well as highlighting challenges that must be overcome for the utilization of graphene deposited on copper substrates by chemical vapour deposition.

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A review of chemical vapour deposition of graphene on copper

Temperature dependence of the mechanical properties of equiatomic solid solution alloys with face-centered cubic crystal structures

Tensile properties of high- and medium-entropy alloys

Recent advances in the understanding of solid-solution hardening (SSH) of crystalline materials, as well as some basic early papers are briefly reviewed. This survey shows that models of SSH based on the concept of a frictional drag on dislocations migrating through fields of point-like obstacles, whether randomly dispersed or clustered, do not encompass the principal features of SSH, e.g. the temperature dependence of the yield stress, the stress and temperature dependences of the activation volume, and the phenomenon of stress equivalence. However, a model based on the nucleation of slip, involving the breakaway of dislocation segments from several pinning points, formulated in closed form, is shown to account satisfactorily for the principal observations.

Muhammad Zakria Butt

Papers

Solid-solution hardening

Solid-solution hardening

Optical and electrical properties of NiO and Cu-doped NiO thin films synthesized by spray pyrolysis

Synthesis and characterization of sol-gel derived La and Sm doped ZnO thin films: A solar light photo catalyst for methylene blue

Solid-solution hardening in dilute alloys