Local variations of lattice parameter and long-range internal stresses during cyclic deformation of polycrystalline copper

Journal Article · Wed Sep 01 00:00:00 EDT 1993 · Acta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-7151(93)90143-G· OSTI ID:6269431

Biermann, H; Pfannenmueller, T; Hoffman, G; Mughrabi, H ^[1]; Ungar, T; Borbely, A ^[2]

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1. Univ. Erlangsten-Nuernberg, Erlangen (Germany). Inst. fuer Werkstoffwisenschaften
2. Eoetvoes Univ. Budapest, Budapest (Hungary). Inst. for General Physics

X-ray line profiles and line positions were measured on single grains of cyclically deformed polycrystalline copper specimens unloaded from characteristic points of the stress-strain hysteresis loop. A high-resolution double crystal diffractometer was used to obtain local lattice parameter changes, from which long-range internal stresses and mean stresses were evaluated. In the case of samples unloaded from the load-reversal points the asymmetry of the characteristically broadened X-ray line profiles indicated forward and backward internal stresses prevailing in the dislocation cell walls and cell interiors of the dislocation cell structure, respectively. The changes of the long-range internal stresses after unloading from different points of the stress-strain hysteresis loop can be explained in terms of the composite model. In addition, mean strains and stresses, varying from grain to grain, could be determined from the shifts of the Bragg reflections. A detailed microstructure-abased discussion of the elastic stored energy, evaluated from the analysis of the stress-strain hysteresis loop, is given.

• OSTI ID: 6269431
• Journal Information: Acta Metallurgica et Materialia; (United States), Vol. 41:9; ISSN 0956-7151
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COPPER
LATTICE PARAMETERS
STRESSES
DEFORMATION
DISLOCATIONS
EXPERIMENTAL DATA
HYSTERESIS
PLASTICITY
STRAINS
X-RAY DIFFRACTION
COHERENT SCATTERING
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DATA
DIFFRACTION
ELEMENTS
INFORMATION
LINE DEFECTS
MECHANICAL PROPERTIES
METALS
NUMERICAL DATA
SCATTERING
TRANSITION ELEMENTS
360102* - Metals & Alloys- Structure & Phase Studies
360103 - Metals & Alloys- Mechanical Properties