Wednesday  |  Allegheny  |  09:00 AM–09:20 AM

#13782, The Effect of ECAE Processing Route on the Dynamic Tensile Response of a Binary Magnesium-Aluminum Alloy

A model magnesium alloy, Magnesium – 6 wt.% Aluminum (Mg-6Al), was subjected to two different Equal Channel Angular Extrusion (ECAE) processing treatments, four passes of the Bc route (4Bc) and four passes of the A route (4A), both under isothermal conditions - 300oC. Miniature dog-bone tensile specimens with gage dimensions of 1 mm long, 0.5 mm wide, and 0.2 mm thick were machined from the extruded billets. These specimens had their gage lengths aligned along one of three orthogonal directions associated with the ECAE process: extrusion (ED), transverse (TD), and longitudinal directions (LD). The specimens were then tested at a strain rate of 10^4 /s, with in-situ high speed camera footage recorded to gain insight to the active deformation and failure processes on the microseconds time scale. The direction-dependent stress--strain responses were compared within and across processing routes. The ultimate tensile strengths were similar for all procesing routes and directions. However, results showed that the 4A samples exhibited a stronger anisotropic response than the 4Bc samples. Specifically, the 4A samples strained along the LD exhibited a sigmoidal stress-strain response while the 4A samples tested along the other two directions displayed a monotonic hardening behavior until failure. The 4Bc samples exhibited similar monotonic hardening behavior regardless of loading direction. A Sachs analysis incorporating measured crystallographic textures of the as-processed materials has been applied to better understand the relationship between changes in microstructural activity and the observed macroscale stress--strain behavior.

Christopher Bond   New Mexico Institute of Mining and Technology
Laszlo Kecskes   Johns Hopkins University
Jamie Kimberley   New Mexico Institute of Mining and Technology