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Information × Registration Number 0200U004393, 0197U017351 , R & D reports Title Investigations of non-regularity phenomena of forming porous powder iron properties popup.stage_title Head Kushchevs'kyj Anatolij Yelysejovych, Registration Date 30-06-2000 Organization Frantzevich Insitute for Materials Science Problems of the Ukranian National Academy of Sciences popup.description2 Subject - powder iron, theoretical and experimental investigations of forming its properties by destructive and non-destructive methods. Distinction of the subject (powder iron) resides in that all test pieces were produced by precision compaction of a basic powder in accordance with the procedure and requirements of ГОСТ 29012 - 91 (ISO 4492 - 85). Aim of the work is to reveal possibility of using the phenomenon of non-regularity in forming powder iron properties in order to improve and optimize the technology of its production. Mechanisms of changes in powder iron properties depending on porosity were investigated by complex of destructive and non-destructive (ultrasound) methods. Their correlation with the structure and other technological, physical and mechanical properties of the compacts produced from powder iron was shown both before and after sintering. Theoretical knowledge of iron and other metal powder compaction in a hard matrix was developed. It is based on the main points of a plasticity theory for powder and porous bodies with using a continuous model. Theoretical knowledge of distinctions of the elastic wave spreading through the porous bodies was developed. Non-destructive acoustic methods of a powder iron investigations were proposed. Mechanisms of changes in acoustic properties of powder iron depending on porosity were ascertained experimentally. Their correlation with the structure and other technological, physical and mechanical properties of produced powder compacts was shown both before and after sintering. It was ascertained that non-regularity in changes (non-monotonous change) of sintered powder iron properties depending on porosity was conditioned by existence of the line of various structures (packs) in the narrow intervals of porosity (1 to 2.5%). Every structure is formed from the individual particles of the basic powders of the compaction stage. Recommendations improving the technology of powder iron production were proposed with allowance for existence of non-monotonous chan ges of powder iron properties depending on porosity.Key words:powder iron, porosity, ultrasound, non-destructive test, crakc resistance, tribotechnical, physical and mechanical properties, deformation, plasticity, stress-deformed state Product Description popup.authors popup.nrat_date 2020-04-03 Close