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Phase stability and mechanical properties of novel high entropy transition metal carbides
- Publication Year :
- 2019
- Publisher :
- eScholarship, University of California, 2019.
-
Abstract
- Twelve different equiatomic five-metal carbides of group IVB, VB, and VIB refractory transition metals are synthesized via high-energy ball milling and spark plasma sintering. Implementation of a newly developed ab initio entropy descriptor aids in selection of candidate compositions for synthesis of high entropy and entropy stabilized carbides. Phase formation and composition uniformity are analyzed via XRD, EDS, S/TEM-EDS, and EXAFS. Nine of the twelve candidates form true single-phase materials with the rocksalt (B1) structure when sintered at 2473 K and can therefore be investigated as high entropy carbides (HECs). The composition (V0.2Nb0.2Ta0.2Mo0.2W0.2)C is presented as a likely candidate for further investigation as an entropy stabilized carbide. Seven of the carbides are examined for mechanical properties via nanoindentation. The HECs show significantly enhanced hardness when compared to a rule of mixtures average of the constituent binary carbides and to the highest hardness of the binary constituents. The mechanical properties are correlated to the electronic structure of the solid solutions, offering a future route to tunability of the mechanical properties of carbide ceramics via exploration of a new complex composition space.
- Subjects :
- Materials science
Polymers and Plastics
High-entropy alloys
Spark plasma sintering
Thermodynamics
02 engineering and technology
01 natural sciences
Carbide
Transition metal
Hardness
0103 physical sciences
Ceramic
Ball mill
Materials
010302 applied physics
High entropy alloys
Mechanical Engineering
Metals and Alloys
Multicomponent
Materials Engineering
Nanoindentation
021001 nanoscience & nanotechnology
Condensed Matter Physics
Electronic, Optical and Magnetic Materials
visual_art
Ceramics and Composites
visual_art.visual_art_medium
Carbides
0210 nano-technology
Solid solution
Entropy-stabilized
Subjects
Details
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....636f5f4cdcd6d17de5c2ee47dd71fbd1