Influence of Rolling Routes on Press Formability of a Rolled AZ31 Mg Alloy Sheet

Abstract

Microstructure, tensile properties and press formability of AZ31 Mg alloy sheets processed by unidirectional rolling, reverse rolling and cross rolling were investigated. The intensity in (0002) plane texture for the reverse-rolled and the cross-rolled specimens was lower than that for the unidirectional-rolled specimen. In addition, the Erichsen values of the formers were larger than those of the latter. The superior press formability for the formers could not be explained from the viewpoint of the elongation to failure, n-value, average r-value and planar anisotropy of the r-value, but it was related to a reduction in directional dependence of the thickness-direction strain and width-direction strain normalized by the tensile-direction strain (" t =" L and " w =" L ). Therefore, it is suggested that the minor texture formation due to reverse rolling and cross rolling gives rise to the reduction in anisotropy of strain, resulting in the superior press formability for the reverse-rolled and cross-rolled specimens.

Improvement of formability of Mg–Al–Zn alloy sheet at low temperatures using differential speed rolling

“…The DSR processing was conducted at a rotation speed ratio of 1.167 without lubrication on roll surfaces, and both rolls were heated to 573 K. The billets were rolled from 4 mm to 2 mm in thickness by 6 passes at 703 K, and then were rolled down to 1 mm by 8 passes at 573 K. The sheet was rotated and reversed after each pass so that the shear strain was introduced unidirectionally throughout the rolling. For comparison, normal rolling was conducted under the same rolling schedule and the rolling direction was reversed after each pass, which has been reported to exhibit a better stretch formability in comparison with the unidirectional normal rolling [17]. All as-rolled sheets were subsequently annealed at 573 K for 3 h, and then were subjected to optical microscopic observation, X-ray texture analysis, tensile test and formability evaluations.…”

Excellent room-temperature ductility and formability of rolled Mg–Gd–Zn alloy sheets

“…7(c) and (d) are the top view of the rolled Mg-Gd-Zn alloys after the Erichsen tests. Previous study [28] revealed that a rolled AZ31 Mg alloy having a basal texture with a splitting of basal pole toward the RD exhibits a surface crack parallel to the RD after Erichsen tests. However, in the present study, the surface crack parallel to the TD appeared in all the rolled Mg-Gd-Zn alloys.…”

Hot Deformation Mechanisms and Microstructural Control in High‐Temperature Extruded AZ31 Magnesium Alloy

“…[1] Out of the wrought magnesium alloys, Mg-3Al-1Zn (AZ31) is considered to be the work-horse and considerable emphasis is being given to develop processing-microstructure-mechanical property correlations for this alloy. [2][3][4][5][6][7][8][9][10][11] Since magnesium alloys have limited ductility at room temperature, forming is generally done at elevated temperatures, the most common method being extrusion. [12][13][14][15] AZ31 alloy is commercially extruded at a temperature of about 300°C, [12] which results in a fine grained microstructure and a fiber texture with <10 1 0>direction parallel to the extrusion direction (ED).…”