THE STRESS-STRAIN STATE DURING DIRECT EXTRUSION OF POROUS POWDER BILLETS
DOI:
https://doi.org/10.20535/2305-9001.2012.64.44373Keywords:
extrusion, porous powder billet, plasticity theory, backpressure, stress, deformationAbstract
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.References
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