Materials Science & Engineering A 799 (2021) 140012 Available online 11 August 2020 0921-5093/© 2020 Elsevier B.V. All rights reserved. Thermal stability, microstructure and texture evolution of thermomechanical processed AlCoCrFeNi 2.1 eutectic high entropy alloy M.H. Asoushe a , A. Zarei Hanzaki a, * , H.R. Abedi b, * , B. Mirshekari a , T. Wegener c , S. V. Sajadifar c , T. Niendorf c a Hot Deformation and Thermomechanical Processing Laboratory of High-Performance Engineering Materials, School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran b School of Metallurgy & Materials Engineering, Iran University of Science and Technology (IUST), Tehran, Iran c Universit¨ at Kassel, Institut für Werkstofftechnik (Materials Engineering), 34125, Kassel, Germany A R T I C L E INFO Keywords: Eutectic high entropy alloy Cast structure Thermal stability Thermomechanical processing Texture evolution ABSTRACT The microstructural and texture evolutions of as-cast AlCoCrFeNi 2.1 eutectic high entropy alloy (EHEA) have been investigated in the course of thermomechanical processing at the temperature range of 25–500 ◦ C. Inter- estingly, compared with other conventional casting structures, signifcant strength-ductility ratio has been achieved at room temperature. In addition, the volume fractions of the constituent phases: soft FCC (face- centered cubic), and the hard BCC (body-centered cubic) phases, do not signifcantly change from room to elevated deformation temperatures. In fact, the strength and ductility have not been decreased at higher tem- peratures which represent the mechanical stability of the alloy in the examined temperature range. From room temperature up to 300 ◦ C, the dendrites have been stretched and broken with a slight deviation from the load direction, whereas at higher temperature of 500 ◦ C the dendrites have been rotated relative to the direction of load before fracture. Texture examination reveals the formation of a random texture in the initial and deformed states due to simultaneous contribution of different infuencing factors such as stretching of dendrites during deformation, the dendrite morphology changes, and the presence of hard and soft phases and their interaction with each other. 1. Introduction Owing to the limited resources, the development of new materials has drawn much attention as the mainly upfront challenge of the next generation. Conventional alloys are based on one or two main elements with relatively small amount of alloying elements for modifcation of the evolved microstructure [1]. However, the high entropy alloys (HEAs) are a new class of materials which are commonly defned as alloys containing four or more elements with equimolar or near-equimolar compositions; with atomic fraction between 5 and 35 at.% for each element forming a single or dual phase structure despite multiple ele- ments [2,3]. There are mainly four core effects that distinguish this category of alloys from the conventional ones: (i) high-entropy effect (ii) sluggish diffusion (iii) severe lattice distortion and (iv) cocktail effect [3]. Previous researches have shown promising properties of HEAs such as signifcant mechanical properties, noticeable corrosion and wear resistance, thermal stability at elevated temperatures [4,5], and sluggish diffusion kinetics [6]. These specifed properties categorize HEAs as a suitable candidate for high temperature applications. The balance between the strength and ductility is considered as a main challenge to schedule the processing routes of HEAs [7]. In this regard, single phase solid solution FCC structured HEAs show merely good ductility [8,9] while single-phase solid solution BCC structured HEAs possess high strength [10]. Therefore a proper combination of the constituent phases (BCC and FCC phase fractions) can signifcantly enhance mechanical properties [11]. However, simply introducing a combination of FCC and BCC phases, without a proper structural design, could not solve the problem [12]. Besides, the problems resulting from casting e.g. segregation and shrinkage cavities may cause deterioration and heterogeneity in mechanical properties [13,14]. To overcome this problem, the eutectic HEAs alloys have been developed which beneft from acceptable cast-ability [3]. Since the eutectic reaction is an isothermal transformation, there is no solidifcation temperature range and both the segregation and shrinkage cavity can be alleviated [7]. The * Corresponding authors. E-mail addresses: zareih@ut.ac.ir (A.Z. Hanzaki), habedi@iust.ac.ir (H.R. Abedi). Contents lists available at ScienceDirect Materials Science & Engineering A journal homepage: http://www.elsevier.com/locate/msea https://doi.org/10.1016/j.msea.2020.140012 Received 19 May 2020; Received in revised form 27 July 2020; Accepted 28 July 2020