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Production of Amorphous Alloys by Special Electrometallurgy Methods Shapovalov V., Nikitenko Y., Manulyk A., Kalashnyk D. E.O. Paton Electric Welding Institute of the NAS of Ukraine ABSTRACT Fast-quenched alloys with amorphous and microcrystalline structures were obtained by the cooling drum spinning method during plasma-arc melting process. Thermal load measurements carried out during the melting process and the spinning of the molten material that followed, helped us to modify the existing plasma-arc equipment. Metallographic analyses of the amorphous alloys showed the influence of some quenching process parameters on the creation of their microstructure and revealed the nature of the formation of the crystal structures. INTRODUCTION Fast-quenched metals and alloys could belong to the category of amorphous or microcrystalline materials. According to their crystal size, the microcrystalline structures could be classified either as nanocrystalline (grain size less than 100 nm) or as microcrystalline (grain size of up to 100 m). It is known that this group of materials is broadly used in many industries. They are mainly used for soldering in the electronics industry, however, the unique properties of the fast-quenched materials are very attractive for the chemical industry, healthcare, sport tools production, etc. [1]. For example, fast-quenched alloys based on compositions of Ni, Fe, Co, Cr and Nd with B, P, Si and C are widely used in the electronics and power industries for the production of high power electromagnets (Nd-Fe-B), transformer cores (Fe-Si), magnetic sensors, etc. Compared with other equivalent crystalline materials, the fast-quenched amorphous solders have numerous advantages. Some solders based on BNi and Cu-P, with high contents of P, Si and B, have high fluidity and improved wettability in the liquid state, although they have high brittleness in the solid state. Super-fast quenching of molten materials by the spinning method is the most common process to produce amorphous structures. The method consists in the extrusion of a molten material from a quartz crucible with application of positive gas pressure through a nozzle into a rotating cooled drum. The refractory crucible is usually a source of material contaminations and temperature control limitations. EXPERIMENTAL DETAILS Super-thin amorphous ribbons with thicknesses of less than 100 m allow avoiding crosssectional segregation and possess the ability to minimize the soldering gap. This technology offers the opportunity to use numerous super-fast-quenched soldering materials for soldering of multiple cell panels in the rocket industry, construction of elements for nuclear reactors, and other applications. A new plasma-arc technology and equipment have been developed in E.O. Paton Electric Welding Institute of the National Academy of Sciences (NAS) of Ukraine for production of amorphous and nano-crystalline materials (Figure 1).

Figure 1. Plasma-arc installation OP-133. The melting process was conducted in a water-cooled copper crucible (sku