THE STRESS-STRAIN STATE DURING DIRECT EXTRUSION OF POROUS POWDER BILLETS

Л. А. Рябичева, Д. А. Усатюк, Н. В. Белошицкий

Abstract


Computer modelling of stress-strain state, distribution of density in porous powder billet, selection the most appropriate backpressure value for direct extrusion and development of production technology for manufacturing of hollow detail. Design/methodology/approach. The modelling results for direct extrusion of porous powder billets on the basis of plasticity theory are presented. Distributions of stress-strain state parameters and density during direct extrusion of hollow detail from copper porous powder billet were obtained. Enhancement of uniformity of deformation by increasing of backpressure ensures prevention of flowthrough flaw and improvement of equidensity of billet. The modelling results are well concordant with the results of laboratory experiments. Findings. The analytical dependences of backpressure from relative depth of cavity and extrusion pressure from backpressure were recommended. The optimal value of backpressure was found for ensuring the uniform stress-strain state and given density of detail. Originality/value. The production technology for manufacturing of hollow detail by direct extrusion with backpressure has been developed.

Keywords


extrusion; porous powder billet; plasticity theory; backpressure; stress; deformation

References


Golovin V.A., Golovin V.A., Mit'kin A.M., Reznikov A.G., Tehnologija holodnoj shtampovki vydavlivaniem (The technology of cold extrusion). Moscow: Mashinostroenie, 1970. 152 p.

Roman O.V., Roman O.V., Doroshkevich E.A., Zvonarev E.V., Issledovanie processa holodnoj shtampovki vydavlivaniem spechennyh poristyh zagotovok (Investigation of the process of cold extrusion of sintered porous billets ). Powder metallurgy, 1980, no 11, pp. 28-34.

Shtern M.B. Fenomenologicheskie teorii pressovanija poroshkov (The phenomenological theory of compression of powders). Kiev: Naukova dumka, 1982. 140 p.

Skorohod V.V. Reologicheskie osnovy teorii spekanija (Rheological Fundamentals of the theory of sintering). Kiev: Naukova dumka, 1972. 152 p.

Ryabicheva L.A., Tsirkin A.T. Tehnologii izgotovlenija poroshkovyh detalej metodami plasticheskogo deformirovanija (Technology of powder parts by plastic deformation). Lugansk, Izd-vo VNU im. V.Dalja, 2009. 176 p.


GOST Style Citations


1. Головин В.А. Технология холодной штамповки выдавливанием / В.А. Головин, А.М. Митькин, А.Г. Резников. – М.: Машиностроение, 1970. – 152 с.

2. Роман О.В. Исследование процесса холодной штамповки выдавливанием спеченных пористых заготовок / О.В. Роман, Е.А. Дорошкевич, Е.В. Звонарев [и др.] // Порошковая металлургия. – 1980. – №11. – С. 28-34.

3. Штерн М.Б. Феноменологические теории прессования порошков / Штерн М.Б. [и др.] - К.: Наукова думка, 1982. – 140 с.

4. Скороход В.В. Реологические основы теории спекания / В.В. Скороход. – К.: Наукова думка, 1972. – 152 с.

5. Рябичева Л.А. Технологии изготовления порошковых деталей методами пластического деформирования / Л.А. Рябичева, А.Т. Цыркин − Луганск, Изд-во ВНУ им. В.Даля, 2009. − 176 с.





DOI: http://dx.doi.org/10.20535/2305-9001.2012.64.44373

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