Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1573361 | Materials Science and Engineering: A | 2016 | 12 Pages |
Abstract
The present work investigates the influence of different shearing patterns on mechanical and forming behavior at room temperature of equal channel angular pressing (ECAP) processed AZ31 sheets. Hot-rolled AZ31 (Mg-3Al-1Zn, wt%) sheets, with dimensions of 200Ã200Ã1.8 mm3, were processed at 225 °C with channel angle of 110° regarding processing routes A, C and D. Shear deformation induced by ECAP weakens the texture and promotes a broad angular distribution of basal planes in the pressing direction on routes A and C. Especially, processing on route D makes basal planes tilted towards the rolling direction and transverse direction by 90° rotation in the sheet plane. Due to the increased activity of basal slip, ECAP processed sheets exhibit the decrease in yield strength and r-value and increase in uniform strain and n-value in the pressing direction. As a result, route C has the largest uniform elongation in the rolling direction and route D provides a quasi-isotropic hardening behavior at room temperature. The improved formability of the ECAP processed sheets is attributed mainly to low r-value and high n-value. At Nakajima tests, route D provides higher forming limits than the as-rolled sample. The microstructure on route D exhibits a drastic reduction in the fraction of {10â12}-{10â11} double twins. This twinning mode leads to premature failure of the as-rolled sample under biaxial stretching. Consequently, microstructure-texture control induced by ECAP can enhance the cold formability of AZ31 sheets.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Joungsik Suh, José Victoria-Hernández, Dietmar Letzig, Roland Golle, Wolfram Volk,