The variation of subgrain misorientation in aluminum with large steady-state creep strain

High purity aluminum was torsionally deformed to various strains up to 16.33 at a temperature of 644 K in this study. The variation in the dislocation substructure was determined with increasing strain. Recent work revealed that both the subgrain size and density of dislocations not associated with subgrain boundaries remained constant over the range of steady-state strains examined. However, transmission electron microscopy in this work revealed that subgrain boundaries remained constant over the range of steady-state strains examined. However, transmission electron microscopy in this work revealed that subgrain boundaries undergo two types of basic changes during steady-state creep. At the onset of steady-state behavior (epsilon = 0.20) all subgrain boundaries had small misorientations, typically, 0.6. The misorientation across boundaries formed as a result of dislocation accumulation continued to increase well past steady-state up to a strain of about 1.2, where a maximum average value of 1.2 was observed. This suggests that the dislocation spacing in subgrain boundaries is not principally responsible for the creep resistance during five power-law creep. At strains greater than about four, nearly a third of the subgrain boundaries were determined to be high angle boundaries (HAB)

Department dc:contributor.department

Mechanical Engineering

Year dc:date.issued

1986

Author dc:creator

• McMahon, Michael E.

Advisor dc:contributor.advisor

• Kassner, M.E.

Statement dc:rights

• This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.

Language dc:language.iso

en_US

Handle dc:identifier.uri

https://hdl.handle.net/10945/22179

OAI identifier oai:identifier

oai:calhoun.nps.edu:10945/22179