Rapid precipitation in an Al0.5CrFeCoNiCu high entropy alloy. (July 2015)

• Record Type: Journal Article
• Authors: Jones, N. G.; Christofidou, K. A.; Stone, H. J.
• Is Part Of: Materials science and technology. Volume 31:Number 10(2015:Oct.)
• Page Start: 1171
• Page End: 1177
• Publication Date: 2015-07
• Subjects: Materials science -- Periodicals; Microstructure -- Periodicals; Metallurgy -- Periodicals; 620.1105
• DOI: 10.1179/1743284715Y.0000000004
• Languages: German
• ISSNs: 0267-0836

Abstract

<abstract> <title> <x content-type="archive" xml:space="preserve">Abstract</x> </title> <p>The effect of cooling rate on the microstructural evolution of Al_0.5CrFeCoNiCu has been studied using differential scanning calorimetry and scanning electron microscopy. As cast Al_0.5CrFeCoNiCu contained three phases; Cr–Fe–Co–Ni solid solution dendrites, Cu rich interdendritic material and L1₂ precipitates. During cooling at rates between 10 and 50°C min⁻¹, an additional exothermic event, at ∼1010°C, was observed in the heat flow curves. Microstructural examination after cooling revealed the presence of two distinct populations of intragranular precipitates not present in the as cast material. Energy dispersive X-ray spectroscopy indicated that Cu rich precipitates formed within the dendrites, while a Cr–Fe–Co rich phase formed in the interdendritic constituent. Precipitation during cooling at rates approaching 1°C s⁻¹ indicates that the diffusion kinetics of Al_0.5CrFeCoNiCu is not, as previously suggested, sluggish.</p> </abstract>