Strain distribution in copper tensile specimens prestrained in rolling

• Type: Article in International Scientific Journal
• Date: 1997

Authors

Fernandes, JV (Author) Other; Vieira, MF (Author) FEUP

Journal

Title: Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science

Vol. 28

Pages: 1169-1179

ISSN: 1073-5623

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 21 Citations

Scopus - 23 Citations

Scientific classification

CORDIS: Technological sciences > Engineering > Mechanical engineering > Metalurgia Metallurgy

FOS: Engineering and technology > Materials engineering

Other information

Authenticus ID: P-001-BHZ

DOI: 10.1007/s11661-997-0282-4

Abstract (EN): Sequences of orthogonal rolling-tension experiments were performed on polycrystalline copper sheets. The effect of strain path change on subsequent yield and flow behavior has been investigated. Optical microscopy and transmission electron microscopy (TEM) were used to clarify the physical mechanisms occurring during the second deformation. The observed increase in yield stress in reloading was related to the change of slip systems corresponding to the glide of dislocations with a Burgers vector, which had not been active during prestrain. The transient observed in the work-hardening behavior after the path change corresponds to the appearance of disorganization in the dislocation microstructure. It was shown that no special feature of slip behavior inside the grains can be related to the nonhomogeneous surface deformation observed at the beginning of reloading. Also, the plastic instability of prestrained samples corresponding to the maximum load in tension does not seem to be directly controlled by the developed local substructure. The nonuniform deformation observed in reloading was studied using a simplified macroscopic two-zone model. It takes into account the presence of geometrical defects in the samples and considers the importance of the mechanical behavior. The macroscopic results, concerning the delay of starting deformation in some regions, are explained by the model, which allows formulation of an analytical condition necessary for deformation to spread through the length of the sample before necking takes place.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11