Analysing the Twist Extrusion of Porous Blanks Using Modified Theories of Plasticity for Porous Bodies

作者：Kuz'mov A V; Shtern M B; Kirkova E G^*; Beygel'zimer Ya E; Pavlenko D V

来源：Powder Metallurgy and Metal Ceramics, 2016, 54(11-12): 631-640.

DOI：10.1007/s11106-016-9757-4

• plasticity of compressible materials
• twist extrusion
• severe plastic deformation
• powder consolidation

Features of the twist extrusion of blanks containing pores and plane cracks are considered. The effect of flat cracks on the porosity distribution and rate of local loosening during deformation is analyzed. The analysis is conducted using a modified theory of plasticity for porous bodies and the finite-element method. It is established that the porosity distribution is sensitive to the concentration of flat defects. At a certain concentration of plane defects, the porosity distribution is inverted: the porosity is higher at the periphery than at the center. The effect of flat defects on the accumulated strain and, as a result, on the structure refinement is less significant. It is confirmed that using the counter-pressure allows suppressing the growth of defects, reducing the refinement efficiency.

• 出版日期2016-3