Regensburg 2019 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 14: Topical session (Symposium MM): High entropy and compositionally complex alloys

MM 14.7: Vortrag

Dienstag, 2. April 2019, 12:30–12:45, H43

Heat capacity, defect annihilation and tracer diffusion in the Ni–CoCrFeMn system: transition from a dilute solid solution to a high entropy alloy — •Josua Kottke¹, Jonas Lübke¹, Adnan Fareed¹, Daniel Gaertner¹, Mathilde Laurent-Brocq², Loïc Perrière², Łukasz Rogal³, Sergiy V. Divinski¹, and Gerhard Wilde¹ — ¹Institute of Materials Physics, University of Münster, Münster, Germany — ²Université Paris Est, ICMPE (UMR 7182), CNRS, UPEC, F-94320, Thiais, France — ³Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, 30-059 Krakow, Poland

High-entropy alloys, i.e. multicomponent alloys with a large number of constituting elements in equiatomic or nearly equiatomic composition, attract an increased attention as potential structural materials due to their favorable physical and mechanical properties, especially at elevated temperatures. Here, we report on the changes in thermodynamic and kinetic properties regarding the transition from a dilute solid solution to a high entropy alloy.

The true heat capacity and tracer diffusion of all elements are measured in Co₂₀Cr₂₀Fe₂₀Mn₂₀Ni₂₀, Co₁₀Cr₁₀Fe₁₀Mn₁₀Ni₆₀ and Co₂Cr₂Fe₂Mn₂Ni₉₂ and compared to those in pure Ni. Furthermore, the annihilation of deformation-induced vacancies and the recrystallisation kinetics are investigated using differential scanning calorimetry. While tracer diffusion does not reveal any abrupt transition, the defect evolution and the microstructural response are shown to be distinct in the Co₁₀Cr₁₀Fe₁₀Mn₁₀Ni₆₀ alloy.