Authors: Maksym Nizameiev, Iryna Zagorulko, Olexandr Semyrga et al.

Summary: The monograph presents the results of many years of joint experimental research by scientists of the Department of Crystallization (now the Department of Metallurgy of Eutectic and Rapidly hardened Alloys) of the G.V. Kurdyumov Institute for Metal Physics of the National Academy of Sciences of Ukraine and the Chemistry faculty of the Ivan Franko National University of Lviv regarding the establishment of regularities and mechanisms for the formation of thermostable amorphous and nanocrystalline states in highly alloyed iron-based alloys with a high level of physicochemical (strength and corrosion) and electrical properties. The physic-technological basis for obtaining of bulk rods and plates of amorphous, amorphous-nanocrystalline and 100 % nanocrystalline alloys close to eutectic compositions with different degrees of alloying at melt cooling rates from 80 to 3200 K/s with crystal sizes from 10 to 50 nm, has been developed. It was established that the alloys most alloyed with poorly soluble in iron metals Cr, W, Mo (in total ~ 30 at. %), carbon (9.8—15 at.%), with a small content of Y (1.8...2 at. %) and A1 (0.1...1 at. %) are characterized by highest tendency to amorphization and thermal stability. The structure of these alloys after crystallization consists of a mixture of solid station nanocrystals based on α-Fe, metastable Fe3B boride, and Cr23C6 and Fe7C3 carbides. The multiphase structure formed in the initial bulk samples, as well as in the process of nanocrystallization of amorphous ribbons, is characterized by record microhardness values of 17—22 GPa. Using chronopotentiometry, cyclic voltammetry and gravimetry methods, the corrosion resistance of strip and bulk amorphous metal alloys in aqueous 0.5 M solutions of NaCl, KOH, HC1 was investigated. Annealing of AMG at nanocrystallization temperatures leads to a significant decrease in the rate of corrosion in all aggressive environments due to an increase in the chromium concentration, which, together with the main component Fe, forms dense protective layers on the surface. Examples of technology transfer and practical using of developed amorphous and nanocrystalline alloys are presented.

ISBN 978-620-5-52884-6

Responsible institutions: G.V. Kurdyumov Institute for Metal Physics of the NAS of Ukraine

Published: Republic of Moldova : Lambert Academic Publishing

Other institutions: Ivan Franko Lviv National University

Size in pages: 292

Additional information: International scientific edition