Microstructures and Tensile Properties of ECAE-Processed and Forged AZ31 Magnesium Alloy

Abstract

In order to achieve same level of high strength and high ductility as 6061 aluminum forging alloy that is currently used for automobile applications, AZ31 magnesium alloy rod with a large diameter of 40 mm was subjected to ECAE-processing, and the microstructures and mechanical properties of the ECAE-processed specimens were investigated. Furthermore, automobile knuckle arm was produced by forging using the ECAE-processed material, and the mechanical properties of the forged product and their strain rate dependencies were investigated under impact tensile load conditions. 4pass-ECAE-processed specimen has fine and uniform microstructure and a texture whose basal planes are mainly parallel to the extrusion direction with some inclined at angles up to 45 to the extrusion direction. Therefore, they show high ductility even if the tensile direction is parallel to the extrusion direction. The knuckle arm forged using the ECAE-processed material exhibits high elongation even in the high strain rate region. Furthermore, the tensile strength, fracture elongation and absorption energy of the forged product increase with increasing strain rate and their values are higher than those of T6-treated 6061 aluminum forging alloy specified by JIS.

Design and Mechanical Properties Analysis of AA5083 Ultrafine Grained Cams

“…Due to the fact that it is likely that buckling and cracks will occur, the design is carried out in two forging stages: preform and final cam. Cisar et al [22] manufacture a knuckle arm, which forms part of the steering system of an automobile, from ECAP-processed AZ31 magnesium alloy. AZ31 is subjected to up to four ECAP passages at a temperature of 250 °C and then, it is forged at a temperature of 150 °C.…”

“…From ECAP-processed AA6061 (twelve times using route Bc), Kim et al [12] manufacture a micro-gear by extrusion at temperature values of 443 K and 553 K. One of their most remarkable conclusions is that the extrusion process may be carried Cisar et al [22] manufacture a knuckle arm, which forms part of the steering system of an automobile, from ECAP-processed AZ31 magnesium alloy. AZ31 is subjected to up to four ECAP passages at a temperature of 250 • C and then, it is forged at a temperature of 150 • C. One of the aims of this research work is to evaluate the applicability of ECAP-processed materials to the manufacturing of industrial components.…”

Secondary Processing of AZ31 Magnesium Alloy Concomitant with Grain Growth or Dynamic Recrystallization

“…It has been demonstrated that the ECAE process can produce materials with a sub-micro crystalline structure, [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] including magnesium alloys. [18][19][20][21][22][23] Very recently, Cisar et al 25) performed hot forging using ECAE-processed AZ31 alloy at 573 K. They succeeded in fabricating an automobile knuckle arm. However, the forming characteristics have not been analyzed.…”

Suppression of Macroscopic Defects through the Control of Friction between Workpiece and Dies in a Forged Magnesium Alloy Part with Ribs

“…To form various parts of magnesium alloys, methods to fabricate plate-or sheet-form parts with ribs and/or bosses need to be developed, and forging is one of the promising methods to accomplish this. [2][3][4][5][6][7][8] The authors have already successfully fabricated plate-form parts with a boss in magnesium alloys by superplastic forging. 9,10) One of the principal types of defect in closed-die forging is extrusion-type defects, 11) which are formed when centrally located ribs and bosses, formed by extrusion-type flow, draw too much metal from the main body of the forging.…”