The monograph presents the results of many years of joint experimental research by scientists of the Department of Crystallization 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. The physico-technological basis for obtaining of bulk rods and plates of amorphous, amorphous-nanocrystalline and 100% nanocrystalline alloys at melt cooling rates from 80 to 3200 K/s with crystal sizes from 10 to 50 nm, has been developed. 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, HCl was investigated. Examples of technology transfer and practical using of developed amorphous and nanocrystalline alloys are presented.