Structural features of ultrafine powders, generated in conditions of wire electrical explosion
| Parent link: | Korus 2000: proceedings the 4th Korea-Russia International Symposium on Science and Technology, June 27 - July 1, 2000 at the University of Ulsan, Republic of Korea.— , 2000 Part 3 : Machine Parts and Materials Processing.— 2000.— P. 277-279 |
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| Other Authors: | , , , |
| Summary: | During several decades the question of the presence or absence of Laplace compression in particles less than 0.1 microns, has been discussed. A consequence of this compression could be an increase of X-ray density in small particles. The study of the structure of final products of wire electrical explosion (ultrafine powders, UFP) has shown that their X-ray density is lower than for metals in a stable massive condition. It is shown that the metals (Al, Cu), not having polymorphic modifications are characterized by a specific defect type-static displacement of atoms concerning X-ray density, lowered up to 0.1-0.2%. In the case of polymorphism of UFP metals, the crystal modifications with lowered density are stabilized: iron as γ-Fe, tungsten as β-W. As regards formation of chemical compounds, oxide UFPs are also formed with lowered X-ray density (γ-Al2O3 , TiO2) |
| Published: |
2000
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| Subjects: | |
| Format: | Book Chapter |
| KOHA link: | https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=220792 |
| Summary: | During several decades the question of the presence or absence of Laplace compression in particles less than 0.1 microns, has been discussed. A consequence of this compression could be an increase of X-ray density in small particles. The study of the structure of final products of wire electrical explosion (ultrafine powders, UFP) has shown that their X-ray density is lower than for metals in a stable massive condition. It is shown that the metals (Al, Cu), not having polymorphic modifications are characterized by a specific defect type-static displacement of atoms concerning X-ray density, lowered up to 0.1-0.2%. In the case of polymorphism of UFP metals, the crystal modifications with lowered density are stabilized: iron as γ-Fe, tungsten as β-W. As regards formation of chemical compounds, oxide UFPs are also formed with lowered X-ray density (γ-Al2O3 , TiO2) |
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