Evolution of Strain-Induced Microstructure and Texture in Commercial Aluminum Sheet Under Balanced Biaxial Stretching

Published

March 1, 2003

Author(s)

Stephen W. Banovic, Timothy J. Foecke

Abstract

The evoluation of surface topography and crystallographic texture was investigated under balanced biaxial stretching in sheets of aluminum alloy 5052 H32. Two different lots of material, with initial nominal thickness of 1 mm, were tested in the as-received condition. The amount of plastic strain introduced into the material was varied using a modified Marciniak in-plane stretching test. In general, the initial characteristics of the materials were found to be similar, in terms of the microstrucutre and mechanical properties, with the exception of the sheet texture. Rocking curves, or w-scans, obtained using X-ray diffraction techniques showed approximately a 30% difference between the crystallographic textures of the two heats. This variation was observed to have an effect on the additiona roughening of the surface subsequent to deformation. For a given lot of material, the surface roughness was found to be proportional to the magnitude of the strain. However, while the roughening rates for the two lots were similar, the lot having a stronger initial {110} texture component was found to have a linear relationship with the strain level, but instead, two regimes were observed. In the first regime, typically for strains (e) up to 0.05, the orientations were found to rotate quickly away from the cube {001}, copper {112}, and S {123} orientations observed in the as-received sheet toward positions along the a-fiber ( crystallographic direction parallel to the sheet normal). Following the strain level of 0.05, the {110} texture component continued to increase with deformation, but at a decreasing rate up to failure of the sheet. The difference in the grain rotation rates observed did not appear to have an effect on the surface roughening as the relative change of the crystallographic orientations with increasing plastic strain was similar for both heats of material. Instead, it is believed that the grain-to-grain interactions may play a more important role int he surface roughening process.

Citation

Metallurgical and Materials Transactions B-Process Metallurgy and Materials Processing Science

Volume

34 No. 3

Pub Type

Journals

Keywords

aluminum alloys, formability, sheet metal, surface roughness, texture

Citation

Banovic, S. and Foecke, T. (2003), Evolution of Strain-Induced Microstructure and Texture in Commercial Aluminum Sheet Under Balanced Biaxial Stretching, Metallurgical and Materials Transactions B-Process Metallurgy and Materials Processing Science (Accessed December 30, 2024)