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Information × Registration Number 0220U103014, 0119U102527 , R & D reports Title Control of the processes of formation from iron alloys powders the products with complex shapes with increased physical and mechanical properties popup.stage_title Head Loboda Petro I., Доктор технічних наук Registration Date 13-07-2020 Organization National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute" popup.description2 Report: 208 pages, 90 fig., 42 tabl., 108 sources. The object of research - the processes of formation of the microstructure, phase composition and properties of construction steels. The purpose of the work is the establishment of optimal parameters of the MIM processes for the production of products of complex shape with increased physical and mechanical characteristics of strength, plasticity, and fracture toughness by purposeful control of phase composition, processes of purification and reinforcement of grain boundaries fibers, microstructure, strained-deformed state and properties of sintered structure chemical inhomogeneity of pressing depending on the parameters of the processes of technological operations: the heating rate, sintering temperature, holding time and heat treatment has been studied. It is established that the source materials "Catamold 8740" and "PolyPoM8740" is a mechanical mixture of powder particles (base - carbonyl iron, ligature - Fe-Mo, Fe-Cr, Fe-Si-Mo, Fe-Si, Ni, etc. .) this leads to a large chemical inhomogeneity of the sintered green compact, which activates a locally inhomogeneous seal in the volume of the material. Microscopic analysis showed that with increasing the heating rate of the ingots of the powder mixture "Catamold 8740" from 2°C/min to 5°C/min decreases the heterogeneity of the microstructure due to locally inhomogeneous compaction and activates alloying at temperatures of 900°C - 1340°C. It is shown that the impact strength increases with increasing sintering temperature and heating rate from 10.39 J/cm2 to 11.52 J/cm2. Heat treatment for materials "Catamold8740" and "PolyPOM8740" significantly reduces residual macrostresses and they do not exceed ~ 150-200 MPa. Based on the obtained results, the parameters of the powder sintering process after injection moulding are optimized. Product Description popup.authors Soloviova Tetiana O. Trosnikova Iryna Yu popup.nrat_date 2020-10-01 Close