Using X-ray microbeam diffraction to study the long-range internal stresses in aluminum processed by ECAP

Lee, I-Fang, Phan, Thien, Levine, Lyle E., Tischler, Jonathan Z., Geantil, Peter T., Huang, Yi, Langdon, Terence G. and Kassner, Michael E. (2013) Using X-ray microbeam diffraction to study the long-range internal stresses in aluminum processed by ECAP. Acta Materialia, 61, 7741-7748. (doi:10.1016/j.actamat.2013.09.013).

Abstract

Aluminum alloy 1050 was processed by equal-channel angular pressing (ECAP) using a single pass (equivalent uniaxial strain of about 0.88). Long-range internal stresses (LRISs) were assessed in the grain/subgrain interiors using X-ray microbeam diffraction to measure the spacing of {5 3 1} planes, with normals oriented approximately +27.3°, +4.9° and ?17.5° off the pressing (axial) direction. The results are consistent with mechanical analysis that suggests the maximum tensile plastic-strain after one pass is expected for +22.5°, roughly zero along the pressing axis, and maximum compressive strain for the ?67.5° direction. The magnitude of the measured maximum compressive long-range internal stress is about 0.13?a (applied stress) in low-dislocation regions within the grain/subgrain interiors. This work is placed in the context of earlier work where convergent beam electron diffraction was used to analyze LRISs in close proximity to the deformation-induced boundaries. The results are complementary and the measured stresses are consistent with a composite model for long-range internal stresses.

This record has no associated files available for download.

Contributors

Author: Yi Huang

Author: Terence G. Langdon

Download statistics