Nanostructured AlCoFeCrVNi and AlCoFeCrVTi high-entropy alloys resulted from mechanical alloying and sintering
| Autor: | V. V. Cherniavsky, A. I. Yurkova, S. O. Nakonechnyi, V. V. Kushnir |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Materials Science (miscellaneous) High entropy alloys Alloy Metallurgy Sintering 02 engineering and technology Cell Biology engineering.material 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Indentation hardness Atomic and Molecular Physics and Optics Nanocrystalline material 0104 chemical sciences Carbide Phase (matter) engineering Electrical and Electronic Engineering Physical and Theoretical Chemistry 0210 nano-technology Biotechnology Solid solution |
| Zdroj: | Applied Nanoscience. 12:849-860 |
| ISSN: | 2190-5517 2190-5509 |
| DOI: | 10.1007/s13204-021-01856-x |
| Popis: | This study reports the structural evolution of AlCoFeCrVNi and AlCoFeCrVTi high-entropy alloys from elemental materials to solid solution phases during mechanical alloying (MA), and further, to equilibrium phases during pressure sintering at 800 °C. The phase and structural transformations in equiatomic powder compositions of the Al–Co–Fe–Cr–V–Ni(Ti) systems during MA and subsequent sintering under high pressure of 5 GPa were studied by X-ray diffraction analysis, scanning and transmission electron microscopy. It was established that the AlCoFeCrVNi(Ti) alloys synthesized by MA consists of a supersaturated bcc solid solutions with nanocrystalline structure and a small amount of WC contaminant was present in both alloys. The bcc solid solutions formed during MA are metastable in nature and transform to a mixture of more stable fcc and bcc solid solutions on consolidation by pressure sintering, and in addition a small amount of (Fe, Cr)23C6 carbide in AlCoFeCrVNi and TiC in AlCoFeCrVTi alloy are formed. Also the WC carbide particles remain in the alloys after sintering. Sintering under high pressure at a relatively low temperature was found to contribute to the maintenance of the nanocrystalline state obtained during MA in compact specimens of both AlCoFeCrVNi and AlCoFeCrVTi alloys exhibited extremely high microhardness of 12.6 and 14.7 GPa and yield strength of 3450 and 4100 MPa, respectively. |
| Databáze: | OpenAIRE |
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