Plastic Behavior and Fracture of Aluminum and Copper in Torsion Tests

Journal Article · Sat Apr 07 04:00:00 UTC 2007 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2729566· OSTI ID:21057055

Bressan, Jose Divo ^[1]

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1. Department of Mechanical Engineering - UDESC Joinville - 89.223-100 Joinville - SC (Brazil)

Present work investigates the plastic behavior, work hardening and the beginning of plastic instabilities, of cylindrical specimens deformed by high speed cold plastic torsion tests and at low speed tensile test. The tests were carried out in a laboratory torsion test equipment and an universal tensile test machine. The tensile tests were performed at room temperature in an universal testing machine at low strain rate of 0.034/s. Experimental torsion tests were carried out at constant angular speed that imposed a constant shear strain rate to the specimen. In the tests, the rotation speed were set to 62 rpm and 200 rpm which imposed high strain rates of about 2/s and 6.5/s respectively. The torsion tests performed at room temperature on annealed commercial pure copper and aluminum. Two types of torsion specimen for aluminum were used: solid and tubular. The solid aluminum specimen curves presented various points of maximum torque. The tubular copper specimens showed two points of maximum. Shear bands or shear strain localization at specimen were possibly the mechanism of maximum torque points formation. The work hardening coefficient n and the strain rate sensitivity parameter m were evaluated from the equivalent stress versus strain curve from tensile and torsion tests. The n-value remained constant whereas the m-value increased ten folds for aluminum specimens: from tensile test m= 0.027 and torsion test m= 0.27. However, the hardening curves were sigmoidal.

• OSTI ID: 21057055
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 907; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM
ALUMINIUM ALLOYS
ANNEALING
COPPER
COPPER ALLOYS
FRACTURES
PLASTICITY
ROTATION
SHEAR
STRAIN HARDENING
STRAIN RATE
STRAINS
STRESSES
TENSILE PROPERTIES
TESTING
TORSION