Tribological Behavior of As-Cast and Aged AlCoCrFeNi2.1 CCA

Abstract

In the present study, wear behavior as a function of aging time was evaluated for the AlCoCrFeNi2.1 eutectic complex, concentrated alloy (CCA) consisting of B2 (BCC), and L12 (FCC) lamellae in the as-cast state. By aging the material at 800 °C up to 500 h, precipitation of a fine, evenly dispersed micro-phase inside the L12 takes place. From 500 h to 1000 h of aging, precipitates coarsen by the Ostwald ripening mechanism. Reciprocating wear tests were characterized by a prevailing abrasive wear mechanism, while adhesive and delamination wear components change with aging conditions. The L12 phase with lower hardness in the as-cast material preferentially deformed during the wear test, which was not the case after aging the material, i.e., with the presence of precipitates. Aging-induced changes show a similar trend for the coefficient of friction and L12 + precipitates phase fraction, whereas changes in specific wear rate are in a good agreement with changes in B2 phase fraction. In general, aging the AlCoCrFeNi2.1 CCA at 800 °C up to 500 h decreases its coefficient of friction due to reduced adhesive wear component and enhances its wear performance through precipitation strengthening.

On the Short-Time Thermal Phase-Stability of As-Cast Alcocrfeni2.1 Eutectic High Entropy Alloy

“…It is generally accepted that coarsening of the precipitates make it harder for dislocations to move through the boundaries which in turn make the material harder [31]. Additionally, decreasing the frequency of the presence of precipitates reduce the probability of dislocationeprecipitate interactions, which lead to lower hardness of the material [32]. As demonstrated in Fig.…”

Complex Concentrated Alloys (CCAs)—Current Understanding and Future Opportunities

“…Eight research articles, four reviews, and one perspective have been published in this special issue of Metals. The subjects are multidisciplinary and divided into several topics including: (i) simulation and modeling for predicting structure and properties [1], (ii) unique deformation mechanisms in multi-principal alloys [2][3][4], (iii) microstructure and properties resulting from various processing routes [5][6][7][8][9][10], (iv) corrosion and surface degradation behavior [11,12], and (v) perspectives on ways to design mechanically and functionally advanced concentrated alloys [13]. Beyramali Kivy et al [1] reviewed the computational tools for studying the structure and properties of multi-principal alloys and identified the advantages as well as limitations of simulations in accelerating design and development of new alloys.…”

“…The processing-microstructure-properties relationship in complex concentrated alloys are discussed in one review article and five research papers in this special issue [5][6][7][8][9][10]. Dong et al [5] reviewed the structure, evolution in properties, and deformation behavior of HEAs after high-pressure treatment (HPT).…”

“…A certain group of concentrated alloys showed phase transformation under high pressure while others remained stable, which indicates unique structural changes and phase transitions in complex concentrated alloys (CCAs) under high pressure. Kafexhiu et al [6] investigated the microstructure and wear behavior of dual phase HEAs as a function of aging time. Maximum hardness and negligible wear were seen for intermediate aging time.…”

МОДЕЛИРОВАНИЕ НАПРЯЖЕННО-ДЕФОРМИРОВАННОГО СОСТОЯНИЯ ВЫСОКОЭНТРОПИЙНОГО СПЛАВА СИСТЕМЫ Al-Co-Cr-Fe-Ni, ОБРАБОТАННОГО ЭЛЕКТРОННЫМ ПУЧКОМ

“…Процесс изготовления ВЭС также оказывает существенное влияние на конечные свойства изделия. Механические свойства эквимолярного сплава AlCoCrFeNi могут изменяться как при варьировании параметров изготовления, так и в зависимости от используемых технологий для получения и последующей обработки [5][6][7]. Поэтому для эффективного внедрения и использования ВЭС в промышленности необходимо выбирать метод изготовления, исходя из требуемых свойств.…”