Influence of alloying elements (Cu, Ti, Nb) on the microstructure and corrosion behaviour of AlCrFeNi-based high entropy alloys exposed to oxygen-containing molten Pb

AbstractFor the past ten years Metalysis have produced tantalum, titanium and titanium alloy powders for high performance applications using their solid state salt electrolysis process. This low energy and environmentally friendly process is now being used to manufacture the next generation of High Entropy Alloys (HEAs).In most cases the manufacture of HEAs involves high temperatures which put all of the alloying elements into the liquid phase. This can lead to numerous problems and restrict the number of HEAs which can be made, particularly the alloys where one needs to combine low melting point elements with refractory elements and also where there are significant liquid density differences between the constituents causing melt segregation.The aim is to present the preliminary work carried out by Metalysis and to show how the solid state diffusion process based on molten salt electrolysis lends itself to the industrial scale manufacture of the next generation of HEAs. This study will focus on the HEAs whose constituent alloying elements have large differences in both their melting points and liquid densities, for example, chromium, niobium, tantalum, titanium and aluminum.

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Effect of the aluminium content of AlxCrFe1.5MnNi0.5 high-entropy alloys on the corrosion behaviour in aqueous environments

Corrosion Science ◽

10.1016/j.corsci.2008.04.011 ◽

2008 ◽

Vol 50 (7) ◽

pp. 2053-2060 ◽

Cited By ~ 170

Author(s):

C.P. Lee ◽

C.C. Chang ◽

Y.Y. Chen ◽

J.W. Yeh ◽

H.C. Shih

Keyword(s):

Corrosion Behaviour ◽

Aluminium Content ◽

High Entropy Alloys ◽

High Entropy ◽

Aqueous Environments

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Effect of the Annealing Treatment on the Microstructure, Microhardness and Corrosion Behaviour of Al0.3CrFe1.5MnNi0.5 High-Entropy Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.748.79 ◽

2013 ◽

Vol 748 ◽

pp. 79-85 ◽

Cited By ~ 2

Author(s):

L.C. Tsao ◽

C.S. Chen ◽

Kuo Huan Fan ◽

Yen Teng Huang

Keyword(s):

Corrosion Behaviour ◽

Dendritic Structure ◽

Annealing Treatment ◽

Age Hardening ◽

High Entropy Alloy ◽

Second Phase ◽

High Entropy Alloys ◽

High Entropy ◽

Fcc Phase ◽

Bcc Phase

In this study, an Al0.3CrFe1.5MnNi0.5high entropy alloy was synthesized by arc-melting in Ar. The as-cast alloy ingot was heat treated for 8 h at 650-750°C and then cooled in furnace to investigate the effects of age treatment on the microstructure, hardness and corrosion behaviour. The microstructure of as-cast sample has a typical rich-Cr BCC structure of dendrites, rich-Ni FCC interdendrite phases and a small fraction of cross-like rich-Ni FCC phase within the majority dendritic structure. During annealing treatment at 650°C, the cross-like FCC phase (β-FCC) gradually decreased, dendritic rich-Cr BCC phase transfers to Cr5Fe6Mn8phase, and the AlNi phase precipitated within the matrix dendrites. The interdendritic β1-FCC phases gradually decomposed and transfers to second-phase (β2FCC), and the AlNi precipitated phase coarsen during annealing at 750°C. In addition, Cr5Fe6Mn8phase gradually transfers to rich-Cr BCC phase during slow-cooling process. These precipitation phases in the grain matrix are the main age hardening mechanism. The potentiodynamic polarization of the Al0.3CrFe1.5MnNi0.5high entropy alloys, obtained in 3.5% NaCl solutions, clearly revealed that the corrosion resistance increases and the passive region decreases as annealing temperature increasing.

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