Structure and Mechanical Properties of AlMg4.5 And AlMg4.5Mn Wires Extruded by Kobo Method

Archives of Metallurgy and Materials

K. Pieła¹  L. Błaz¹  M. Jaskowski¹ 

[1] AGH UNIVERSITY OF SCIENCE AND TECHNOLOGY, DEPARTMENT OF MATERIALS SCIENCE AND NON- FERROUS METALS ENGINEERING, AL. A. MICKIEWICZA 30, 30-059 KRAKOW, POLAND

关键词: Keywords: aluminium alloys;    extrusion;    KoBo method;    structure;    mechanical properties;    work hardening;   

DOI  :  10.2478/amm-2014-0078

学科分类：金属与冶金

来源: Akademia Gorniczo-Hutnicza im. Stanislawa Staszica / University of Mining and Metallurgy

【 摘 要 】

The influence of the number of extrusion steps in KoBo method (at the same total extrusion ratio of λ = 100) on structure, mechanical properties and work hardening characteristics of AlMg4.5 and AlMg4.5Mn (AA5083) alloys was investigated. It was found that one-step extrusion leads to the formation of recrystallised structure of the material, while the use of two-step extrusion yields a fibrous structure of a “mixed” type, i.e. containing areas where the intensive recovery effects are associated with partially recrystallised structure. As a consequence, the strength properties of the latter extrudate are much higher in both as extruded state and after the subsequent cold rolling. In all cases, the tensile stress-strain curves of the extrudates show the flow stress serrations that are typical for the Portevin - LeChatelier (P-L) effect. In a few tensile tests, the P-L effect was preceded by the plastic flow instability being typical for the occurrence of Lüders bands. Both AlMg4.5 and AlMg4.5Mn extruded wires show a monotonic increase of the work hardening that results from the following cold deformation in the groove rolling.

【 授权许可】

Unknown