X-Ray microbeam diffraction study of long-range internal stresses in equal-channel angular pressed aluminum

Published

November 1, 2013

Author(s)

Lyle E. Levine, I-Fang Lee, Thien Phan, Jonathan Z. Tischler, Peter Geantil, Yi Huang, Terrance G. Langdon, Michael E. Kassner

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 (LRIS) were assessed in grain/subgrain interiors by measuring the spacing of {531} planes that are oriented approximately +27.3°, +4.9°, and -17.5° off the extrusion (axial) direction using x-ray microbeam diffraction. The results are consistent with mechanical analysis that suggests that the maximum tensile strain after one pass is expected for +22.5o, roughly zero along the extrusion axis, and maximum compressive for the -67.5o direction. The magnitude of the measured maximum compressive long-range internal stress is about 0.13 σa (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 (CBED) was used to analyze LRIS at the deformation-induced boundaries. The results are complementary and the measured stresses are consistent with a composite model for long-range internal stresses.

Citation

ACTA Materialia

Volume

61

Issue

19

Pub Type

Journals

Keywords

ECAP, microbeam X-ray, stress

Citation

Levine, L. , Lee, I. , Phan, T. , Z., J. , Geantil, P. , Huang, Y. , Langdon, T. and Kassner, M. (2013), X-Ray microbeam diffraction study of long-range internal stresses in equal-channel angular pressed aluminum, ACTA Materialia (Accessed December 26, 2024)