https://dc.engconfintl.org/cgi/viewcontent.cgi?article=1032&context=superalloys_ii

A critical review of high entropy alloys and related concepts

High-entropy alloys (HEAs) are a relatively new class of materials that have gained considerable attention from the metallurgical research community over recent years They are characterised by their unconventional compositions, in that they are not based around a single major component, but rather comprise multiple principal alloying elements Four core effects have been proposed in HEAs: (1) the entropic stabilisation of solid solutions, (2) the severe distortion of their lattices, (3) sluggish diffusion kinetics and (4) that properties are derived from a cocktail effect By assessing these claims on the basis of existing experimental evidence in the literature, as well as classical metallurgical understanding, it is concluded that the significance of these effects may not be as great as initially believed The effect of entropic stabilisation does not appear to be overarching, insufficient evidence exists to establish the strain in the lattices of HEAs, and rapid precipitation observed in some HEAs sug

https://www.tandfonline.com/doi/pdf/10.1080/09506608.2016.1180020

High-entropy alloys: a critical assessment of their founding principles and future prospects

Functionally graded materials: A review of fabrication and properties

Vibration characteristics of functionally graded cylindrical shells under various boundary conditions

Experimental and theoretical investigations have demonstrated that a quasi-two-dimensional electron gas (q-2DEG) can form at the interface between two insulators: non-polar SrTiO3 and polar LaTiO3 (ref. 2), LaAlO3 (refs 3-5), KTaO3 (ref. 7) or LaVO3 (ref. 6). Electronically, the situation is analogous to the q-2DEGs formed in semiconductor heterostructures by modulation doping. LaAlO3/SrTiO3 heterostructures have recently been shown to exhibit a hysteretic electric-field-induced metal-insulator quantum phase transition for LaAlO3 thicknesses of 3 unit cells. Here, we report the creation and erasure of nanoscale conducting regions at the interface between two insulating oxides, LaAlO3 and SrTiO3. Using voltages applied by a conducting atomic force microscope (AFM) probe, the buried LaAlO3/SrTiO3 interface is locally and reversibly switched between insulating and conducting states. Persistent field effects are observed using the AFM probe as a gate. Patterning of conducting lines with widths of approximately 3 nm, as well as arrays of conducting islands with densities >10(14) inch(-2), is demonstrated. The patterned structures are stable for >24 h at room temperature.

/pdf/nanoscale-control-of-an-interfacial-metal-insulator-4krnzbxlgp.pdf

Zhonghong Lai

Papers

Fabrication of ZrO2–NiCr functionally graded material by powder metallurgy

An experimental study of deformation mechanism and microstructure evolution during hot deformation of Ti–6Al–2Zr–1Mo–1V alloy

First-principles studies of the structural, elastic, electronic and thermal properties of Ni3Nb

Alloying effect on phase stability, elastic and thermodynamic properties of Nb-Ti-V-Zr high entropy alloy

FEM simulation of quenching process in A357 aluminum alloy cylindrical bars and reduction of quench residual stress through cold stretching process