Abstract
High-performance structural materials are critical to the development of transportation, energy, and aerospace. In recent years, newly developed high-entropy alloys with a single-phase solid-solution structure have attracted wide attention from researchers due to their excellent properties. However, this new material also has inevitable shortcomings, such as brittleness at ambient temperature and thermodynamic instability at high temperature. Efforts have been made to introduce a small number of intermetallic compounds into single-phase solid-solution high-entropy alloys as a secondary phase to their enhance properties. Various studies have suggested that the performance of high-entropy alloys can be improved by introducing more intermetallic compounds. At that point, researchers designed an intermetallic compound-strengthened high-entropy alloy, which introduced a massive intermetallic compound as a coherent strengthening phase to further strengthen the matrix of the high-entropy alloy. Inspired from this, Fantao obtained a new alloy—high-entropy intermetallics—by introducing different alloying elements to multi-principalize the material in a previous study. This new alloy treats the intermetallic compound as the main phase and has advantages of both structural and functional materials. It is expected to become a new generation of high-performance amphibious high-entropy materials across the field of structure and function. In this review, we first demonstrate the inevitability of intermetallic compounds in high-entropy alloys and explain the importance of intermetallic compounds in improving the properties of high-entropy alloys. Secondly, we introduce two new high-entropy alloys mainly from the aspects of composition design, structure, underlying mechanism, and performance. Lastly, the high-entropy materials containing intermetallic compound phases are summarized, which lays a theoretical foundation for the development of new advanced materials.
Highlights
The developments of transportation, energy, and aerospace are highly dependent on the availability of new structural materials that can offer light weight, high-temperature strength, creep resistance, and oxidation resistance [1,2,3,4,5]
Nickel-based superalloys are commonly used materials that offer most of these properties; there is an issue where it is easy for nickel-based superalloys to form unwanted precipitates or harmful phases during high-temperature applications, and these can reduce the strength significantly [6]
To better develop intermetallic compound-strengthened high-entropy structural materials, researchers have developed a CALPHAD (Calculation of Phase Diagrams) technique based on thermodynamic calculations, which provides an effective method for predicting the phase relationship of multiple-principal-element alloy materials [85,89,100,101,102]
Summary
The developments of transportation, energy, and aerospace are highly dependent on the availability of new structural materials that can offer light weight, high-temperature strength, creep resistance, and oxidation resistance [1,2,3,4,5]. Nickel-based superalloys are commonly used materials that offer most of these properties; there is an issue where it is easy for nickel-based superalloys to form unwanted precipitates or harmful phases during high-temperature applications, and these can reduce the strength significantly [6]. It is necessary to develop new high-temperature structural materials with better performance and stronger stability. After providing the significance of intermetallic compounds in high-entropy materials, two new high-entropy materials containing more intermetallic compounds are introduced from the aspects of composition design, microstructure, properties, strength, and toughness mechanism. Existing problems of the two new materials are summarized prior to stating the potential future development and application prospects
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
