Effect of Temper Condition on Stress Relaxation Behavior of an Aluminum Copper Lithium Alloy

Mishra, Sumeet and Beura, Vikrant Kumar and Singh, Amit and Yadava, Manasij and Nayan, Niraj (2018) Effect of Temper Condition on Stress Relaxation Behavior of an Aluminum Copper Lithium Alloy. In: METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 49A (7). pp. 2631-2643.

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Abstract

Deformation behavior of an Al-Cu-Li alloy in different temper conditions (solutionized and T8) is investigated using stress relaxation tests. Fundamental parameters such as the apparent and physical activation volume, strain rate sensitivity, effective stress, and exhaustion rate of mobile dislocation density are determined from single and multiple relaxation tests. It was found that dislocation-dislocation interaction controls the kinetics of plastic deformation in the solutionized sample, whereas dislocation-precipitate interaction is the overriding factor in the presence of T-1 precipitates. The apparent activation volume was found to be significantly lower in the presence of T-1 precipitates compared with solutionized samples. Strain rate sensitivity and effective stress were found to be higher in the presence of T-1 precipitates. In addition, multiple relaxation tests showed that irrespective of microstructural features (solutes, semi-coherent precipitates), the mobile dislocation density reduces during the relaxation period. Further evidence regarding reduction in mobile dislocation density is obtained from uniaxial tensile tests carried out after stress relaxation tests, where both solutionized and T8 samples show an increase in strength. Additional discussion on relaxation strain is included to provide a complete overview regarding the time-dependent deformation behavior of the Al-Cu-Li alloy in different temper conditions.

Item Type:	Journal Article
Publication:	METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
Publisher:	SPRINGER, 233 SPRING ST, NEW YORK, NY 10013 USA
Additional Information:	Copy right of this article belong to SPRINGER, 233 SPRING ST, NEW YORK, NY 10013 USA
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	25 Jun 2018 15:53
Last Modified:	25 Jun 2018 15:53
URI:	http://eprints.iisc.ac.in/id/eprint/60076

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