Influence of chemical composition and the processing conditions on structure, thermal stability and mechanical properties of rapidly cooled Al-TM-RE-based alloys

The results of t studies are directed to development of new competitive amorphous and nanocrystalline alloys as well as to improvement of technology of their manufacturing. The physical and technological aspects of interrelations between the conditions for production of rapidly quenched alloys, formation of different structural and phase states, and their properties are discussed. The influence of the chemical composition of alloys and the conditions of their quenching on the glass-forming ability, phase composition, and the structure of the rapidly cooled specimens is investigated; the regularities of the effect of alloying elements concentration on the structural features of the Al75–87(Ni,Co,B/Ga)8–20Gd1Y4 alloys obtained by superfast quenching from the liquid state are established. The thermal stability of the rapidly quenched ribbons with an amorphous structure is investigated and the temperature ranges of phase transformations at continuous heating and under isothermal conditions are found. The strength characteristics of the ribbons as a function of the content and nature of alloying elements as well as the melt cooling rate are determined. The methods of obtaining both Al-based bulk nanocrystalline composites with the shapes of rods and plates with thickness of 0.5–3.5 mm and metal matrix hardening coatings are worked out.

Surface Morphology of Spinning Tapes Fe-(Cu, Nb)-(Si, B) with Different Content of Metalloid

Using the methods of spectral analysis with application of the formalism of the integral function of Lebesgue measures and Kullback's divergence, the structural features of the interfaces of spinning Fe- (Cu, Nb) - (Si, B) tapes with different metalloid contents are investigated. An increase in the total concentration of the metalloid ambiguously affects the nature of the morphology of rapidly quenched alloys. The minimum difference in the statistics of contact and free surfaces, formed in the spinning process, is demonstrated by fusionFe74Cu1Nb3Si16B6.

MAGNETIC PROPERTIES AND MAGNETOCALORIC EFFECT OF Fe90-xPrxZr10 RAPIDLY QUENCHED ALLOYS

In this paper, we present the results of studying magnetic properties and magnetocaloric effect of Fe90-xPrxZr10 (x = 1, 2 and 3) rapidly quenched alloys. The alloy ribbons with thickness of about 15 µm were prepared by melt-spinning method on a single roller system. X-ray diffraction patterns of the ribbons manifest their almost amorphous structure. Thermomagnetization measurements show that the Curie temperature of the alloys can be controlled to be near room temperature by changing concentration of Pr (x). When the concentration of Pr is increased, saturation magnetization of the alloys increased from 48 emu/g (with x = 1) to 66.8 emu/g (with x = 2). All the ribbons reveal soft magnetic behavior with low coercive force (Hc < 42 Oe). The magnetic entropy change of the alloys, |∆Sm|max > 0.9 J.kg-1K-1 in magnetic field change DH = 12 kOe, shows large magnetocaloric effect at phase transition temperature. On the other hand, the working temperature range is quite large (dFWHM ~ 70 K) revealing an application potential in magnetic refrigeration technology of these alloys.