High Temperature Deformation of Dispersion Hardened Al-Mg Alloys

Superplasticity refers to a high temperature deformation process involving a marked sensitivity of the flow stress to the imposed strain rate, with resulting enhanced ductility. Although conventionally associated with fine-grained materials, superplasticity has recently been observed in coarse-grained alloys. The present research involves the deformation behavior of Al-Mg base alloys, where superpure Al-3%Mg and Al-5%Mg, and commercial Al 5056 were selected for study. The results for the Al-5%Mg and Al 5056 alloys are presented in this article. Flat sheet-type samples were tensile tested to 10% strain at increasing temperatures and at prescribed strain rates (0.001/s, 0.01/s, and 0.1/s). The dependence of flow stress on temperature was found to display some unusual characteristics. This behavior is interpreted as resulting from the occurrence of dynamic strain ageing (DSA). The aim of the overall study is to determine the relation between DSA and superplasticity in coarse-grained Al-Mg alloys. This will, in turn, lead to the control of the strain ageing behavior so as to produce the largest possible values of strain rate sensitivity (and, hence, elongation).

Download Full-text

High temperature deformation behavior of Al–Cu–Mg alloys micro-alloyed with Sn

Materials Science and Engineering A ◽

10.1016/j.msea.2010.01.052 ◽

2010 ◽

Vol 527 (10-11) ◽

pp. 2498-2503 ◽

Cited By ~ 46

Author(s):

Sanjib Banerjee ◽

P.S. Robi ◽

A. Srinivasan ◽

Lakavath Praveen Kumar

Keyword(s):

High Temperature ◽

Deformation Behavior ◽

Mg Alloys ◽

High Temperature Deformation ◽

Temperature Deformation

Download Full-text

The Role of Dislocation Climb in the High Temperature Deformation of Mg alloys AZ31B and ZK10 and the Distinctions in the Activity of Dislocations with a c-type Burgers Vector

10.26226/morressier.60993d930d0b548838eef4cb ◽

2021 ◽

Author(s):

Michael Ritzo ◽

Sean Agnew

Keyword(s):

High Temperature ◽

Dislocation Climb ◽

Mg Alloys ◽

High Temperature Deformation ◽

Temperature Deformation ◽

Burgers Vector

Download Full-text

Large Deformability of Wrought Magnesium Alloys: Is Superplasticity Needed?

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.433.267 ◽

2010 ◽

Vol 433 ◽

pp. 267-272 ◽

Cited By ~ 2

Author(s):

R. Boissière ◽

Jean Jacques Blandin ◽

Luc Salvo

Keyword(s):

High Temperature ◽

Strain Rate ◽

Magnesium Alloys ◽

Rate Sensitivity ◽

Solute Drag ◽

Mg Alloys ◽

High Temperature Deformation ◽

Temperature Deformation ◽

Fine Grained ◽

Superplastic Properties

The deformability of wrought magnesium alloys at room temperature is limited and a way to overcome this limit is to carry out forming operations in warm or hot conditions. In the case of fine grained alloys, superplastic properties can be generally achieved but in this regime, the Mg alloys are sensitive to strain induced cavitation. However, large grained alloys can also exhibit quite large deformabilities when they are deformed at high temperature. This can be due to the fact that on one hand, the Mg alloys may quite easily dynamically recrystallize and on the other hand, that dislocation movements may be controlled by a solute drag effect leading to significant strain rate sensitivity parameters. These various mechanisms of deformation will depend on the composition, the mean grain size and the conditions of deformation (i.e. temperature and strain rate). In this work, the high temperature deformation mechanisms as well as the associated damage mechanisms of two wrought magnesium alloys are discussed.

Download Full-text