Effect of Uniaxial Strain on the Surface Roughness of Pure MG and MG-AZ31 Alloy
Mark R. Stoudt, A -. Munitz, Stephen W. Banovic, Richard J. Fields
Pure Mg and Mg AZ31 alloy samples were deformed in uniaxial tension and the resultant surface topographies were characterized with optical microscopy, scanning laser confocal microscopy (SCLM) and scanning electron microsopy (SEM) techniques. Initial results indicate three principal deformation mechanisms contribute to the development of the critical surface morphology: a) grain boundary rotations that produced surface features with length scales on the order of several hundred microns, b) deformation twins that produced features with length scales on the order of several microns, and c) slip steps within individual grains that produced surface features with length scales on the order of a few hundred nanometers. The surface roughness ananlysis indicated that the magnitude of the disparities in the deformation morphoogy could promote an intense localization of strain in the pure Mg leading to limited room temperature ductility and stretch formability. In contrast, the addition of alloying elements to the pure Mg increased the ducility by controlling the grain size and promoting a more macroscopically homogeneous deformation through suppression of strain localization and enhancement of crystallographic slip. However, the magnitudes of the surface roughness at maximum strain were essentially the same for the two materials. This suggests that the formability of magnesium alloys can be improved and thereby increase their use in automotive applications.
metal forming, scanning laser confocal microscopy, strain localization, surface roughness
, Munitz, A.
, Banovic, S.
and Fields, R.
Effect of Uniaxial Strain on the Surface Roughness of Pure MG and MG-AZ31 Alloy, Magnesium 2004
(Accessed December 6, 2023)