Microstructural evolution and mechanical properties of CoCrFeNiMnTix high‐entropy alloys

Materialwissenschaft und Werkstofftechnik, vol. 52, pp. 441–451

Abstract

Abstract This study was conducted to investigate the effect of titanium addition on the microstructure and properties of an equitaomic CoCrFeNiMn high‐entropy alloy. Homogenized microstructures of CoCrFeNiMnTix (x = 0.1 and 0.3) alloys consist of face‐centered cubic phase; however, addition of more titanium led to formation of a (chromium, titanium)‐rich σ phase in CoCrFeNiMnTi0.4 alloy. The average electron hole number calculations indicate the higher possibility of σ phase formation by adding more titanium. Furthermore, addition of an atom like titanium with a larger atomic radius in comparison with other elements can affect stability of face‐centered cubic structure. Chromium and manganese has a destabilizing influence on the single face‐centered cubic phase and manganese may reject chromium to facilitate the formation of a (chromium, titanium)‐rich phase in alloys containing more than 5.5 at.% titanium (x>0.3). The mechanical properties revealed an improvement in strength without losing the ductility drastically by adding titanium up to 5.5 at.% (x = 0.3). Nevertheless, the strength remarkably increased and ductility significantly decreased in CoCrFeNiMnTi0.4 alloy due to formation of brittle σ phase in the microstructure.

Authors 4

1. Hamed Shahmir corresponding

   Tarbiat Modares University

   Affiliation as printed

   Department of Materials Engineering Tarbiat Modares University P.O. Box 14115-143 TEHRAN IRAN

   Department of Materials Engineering, Tarbiat Modares University, P.O. Box, 14115-143 TEHRAN, IRAN

2. Alireza Derakhshandeh

   University of Tehran

   Affiliation as printed

   School of Metallurgy and Materials College of Engineering University of Tehran P.O. Box 14395-731 TEHRAN IRAN

   School of Metallurgy and Materials, College of Engineering, University of Tehran, P.O. Box, 14395-731 TEHRAN, IRAN

3. Bengt Hallstedt Aachen Institute for Materials Applications in Mechanical Engineering

   RWTH Aachen University

   Affiliation as printed

   Institute for Materials Applications in Mechanical Engineering RWTH Aachen University P.O. Box 52062 AACHEN GERMANY

   Institute for Materials Applications in Mechanical Engineering, RWTH Aachen University, P.O. Box, 52062 AACHEN, GERMANY

4. Mahmoud Nili‐Ahmadabadi

   University of Tehran

   Affiliation as printed

   School of Metallurgy and Materials College of Engineering University of Tehran P.O. Box 14395-731 TEHRAN IRAN

   School of Metallurgy and Materials, College of Engineering, University of Tehran, P.O. Box, 14395-731 TEHRAN, IRAN