Study of Microsegregation in Molybdenum and Tungsten Single Crystals Alloyed by Iridium or Rhenium

• Autorzy: Bujnošková K. , Drápala J.
• Konferencja: International Conference on Modelling in Mechatronics (9 ; 02-04.09.2004 ; Kazimierz Dolny, Poland)
• Języki publikacji: EN

Abstrakty

EN

The convection caused by the temperature and concentration gradients can lead to the creation of microinhomogeneities such as growth cores, striations and cellular structure. Low-alloyed single crystals of W-Ir, Mo-Ir and Mo-Re alloys were prepared by electron beam zone melting applying three zone pass rates: 3, 5 and 1 mm/min. The Electron Microprobe Analysis by Wavelength Dispersive X-ray Spectrometry (Vitkovice - Research and Development Ltd., Ostrava, Cz) and the Instrumental Neutron Activation Analysis (Institute of Nuclear Research, Rez, CZ) were used for the evaluation of admixture distribution on longitudinal sections of specimens. On the basis of chemical analysis, the striations in these single crystals characterized by the sinusoidal wave of concentration profiles were found. Effective distribution coefficients of Re and Ir in molybdenum and tungsten were determined.

Słowa kluczowe

EN

convection in melt; single crystals; molybdenum; tungsten

• Wydawca: Oficyna Wydawnicza Politechniki Warszawskiej
• Czasopismo: Machine Dynamics Problems
• Rocznik: 2004
• Tom: Vol. 28, No. 3
• Strony: 69--75
• Opis fizyczny: Bibliogr. 8 poz.

Twórcy

autor

Bujnošková K.

• VŠB - Technical University of Ostrava, Department of Non-ferrous Metals, Refining and Recycling

autor

Drápala J.

• VŠB - Technical University of Ostrava, Department of Non-ferrous Metals, Refining and Recycling

Bibliografia

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• [2] Děvjatych, G.G., Burchanov, G.S., 1993, Yysokočistyje tugoplavkije i redkije metally. Moskva, Nauka.
• [3] Kuchař, L., Drápala, J., 2000, Metalurgie čistých kovů. Metody rafmace čistých látek. Nadácia R. Kammela, Košice.
• [4] Hein, K., Buhrig, E., Kuchař, L., Barthel, J., 1983, Kristallisation aus Schmelzen. Leipzig, VEB Deutscher Verlag für Grundstoffindustrie.
• [5] Kuchař, L. et al., 1984, Makrosegregation, Mikrosegregation und Substruktur in zonengeschmolzenem Molybdän, in: Sbornlk vědeckých praci Vysoké školy báňské v Ostravé, řada hutnická, VŚB Ostrava, 43-52.
• [6] Bujnošková, K., Drápala, J., Forming and technological processing of single crystals on the base of tungsten and molybdenum, in: Development of Materials Science in Research and Education, Praha: MAXDORF, s.r.o. 80-85912-85-8.
• [7] SGTE Date for Pure Elements, NPL Reports DMA (A), 195, 1989. Binary Alloy Phase Diagrams ASM International Materials Park, Ohio, 1996.
• [8] Elliot, R.P., 1965, Constitution of binary alloys, New York, McGraw-Hill.