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Information × Registration Number 0212U000523, 0107U004065 , R & D reports Title Working out of methods of formation fine-grained structure in ferromagnetic powders of SmCo5-based alloys popup.stage_title Head Bulyk Ihor Ivanovych, Доктор технічних наук Registration Date 21-02-2012 Organization Karpenko Physico-Mechanical Institute of the National Academy of Science of Ukraine popup.description2 The investigation objects are SmCo5 based materials and technology of the treatment under hydrogen atmosphere. The aim of the project is methods development of the samarium-cobalt system nanocrystalline, textured powders production by using hydrogen metallurgy processes for forming high temperature permanent magnets. The studies were carrying out on КС37 commercial ferromagnetic alloy (based on SmCo5 compound). Treatment conditions, phase composition, crystallographic, microstructural and magnetic properties of the SmCo5 based alloy powders were investigated by means of differential thermal, X-ray phase, electron microscopy, elemental analysis and magnetic hysteresis loops measurement. Following methods for fine-grained structure formation for ferromagnetic alloys in samarium-cobalt system were develop by using hydrogen as technological environment: -mechano-chemical treatment of the alloy in planetary mill under hydrogen pressure with further thermal treatment in vacuum; -disproportionation under hydrogen pressure and recombination in vacuum; - combination of the mechano-chemical treatment by means of planetary milling under hydrogen with further thermal hydrogen-vacuum treatment (disproportionation under hydrogen pressure and recombination in vacuum). The mechanism of texture (preferred orientation) formation in ferromagnetic alloys after disproportionation and recombination was found. Preferred orientation in a powders formed after recombination of disproportionated alloy can be realized if the remain of initial phase (<20 %). Optimal parameters of the process textured fine-grained structure formation for the achievement of high magnetic properties in SmCo5 based alloys with grains sizes 60-150 nm were determined: - by means of solid HDDR under hydrogen pressure 0.6-1.0 MPa with duration of hydrogen treatment 2-5 h in temperature range 700-950 °С for the production of powders with coercitivity up to 38 kOe; - by means of combined hydrogen treatment with combination of mechano-chemical milling in planetary mill under hydrogen pressure with further thermal hydrogen-vacuum treatment (rotation frequency of mill chamber 100 rpm, milling duration to 60 min, hydrogen pressure to 0.4 MPa, temperature 640°С, duration to 2 h; recombination temperature to 950 °С) for the production of powders with gains sizes of SmCo5 ferromagnetic phase 40-75 nm and coercitivity 41 кOe. Bases of the new low temperature method of the SmCo5 based powders sintering with the sintering temperature up to 950 °C were developed. Two Ukrainian patents devoted to fine-grained textured methods formation structure were obtained and the third devoted to nanoscale textured structure method formation in SmCo5 based alloys being processed. Developed methods of the nanoscale textured structure formation for SmCo5 based alloys are scientific base for high-performance, composites, nanostructure magnets commercial powders production. Material science aspects of the texture formation in SmCo5 based alloys are bases of the progress in similar works for nanostructure formation in Sm2Co17 based alloys and for anisotropy formation in bulk full density magnets with nanoscale structure. Product Description popup.authors Дмитришин Василь Михайлович Лютий Павло Ярославович Тростянчин Андрій Миколайович popup.nrat_date 2020-04-02 Close