National Research Nuclear University MEPhI, Moscow, Russia:

A. N. Suchkov, Associate Professor, Candidate of Technical Sciences
E. A. Bazdnikina, Engineer, e-mail: eabazdnikina@mail.ru
V. N. Kazakova, Engineer
+B. A. Kalin (1935–2021)

Baikov Institute of Metallurgy and Materials Science at the Russian Academy of Sciences, Moscow, Russia:
A. V. Samokhin, Lead Researcher, Candidate of Technical Sciences

The paper describes a method for obtaining Ti- and Zr-base near-eutectic alloys in the form of powders with a high degree of sphericity and a narrow size distribution of powder particles. Thus, a Zr₃₅Ti₃₀Be_27,5Сu_7,5 alloy powder with a particle sphericity of more than 97% and a particle size distribution of 63–100 μm was produced using the method of plasma spheroidization of fragmented powders obtained by grinding amorphous rapid-quenched strips. The final state of spherical particles has an X-ray amorphous structure, as indicated by a broad halo of scattered intensity typical of amorphous materials. An even distribution of chemical elements across the particle section could be observed. Bulk samples were made using the method of spark plasma sintering and applying varying parameters of temperature and dwelling time. The authors looked at the microstructure and microhardness of the bulk samples and carried out an X-ray phase analysis. The samples were found to have an X-ray amorphous structure during spark plasma sintering in the temperature range of 320 to 340 оC. However, at the temperatures of 320–325 ^оC, the resulting samples have a high internal porosity, which cannot be fixed with a pressure rise. The greatest compaction is achieved at the temperatures of 335 to 340 ^оC. By varying the dwelling time, the authors determined the optimal regime for producing bulk amorphous alloys: sintering at 340 ^оC and the pressure of 50 MPa, dwelling for 15 min followed by cooling at the rate of 80 ^оC/min. The samples produced in the above conditions have no visible porosity, and their microhardness is closest to that registered in cast samples.
Contributors to this research include O. N. Sevryukov, Associate Professor, Candidate of Technical Sciences; P. V. Morokhov, Lead Engineer; P. S. Dzhumaev, Associate Professor, Candidate of Technical Sciences; I. V. Kozlov, Engineer; V. V. Mikhalchik, Senior Lecturer, Candidate of Technical Sciences; D. S. Gorbunov, Senior Lab Assistant (National Research Nuclear University MEPhI); A. A. Fadeev, Research Fellow; I. D. Zavertyaev, Junior Researcher (Baikov Institute of Metallurgy and Materials Science at the Russian Academy of Sciences).

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