Journal of Materials Engineering and Performance

, Volume 20, Issue 9, pp 1569–1574 | Cite as

Tensile Behavior of Ultrafine-Grained Al-4Zn-2Mg Alloy Produced by Cryorolling

  • K. Gopala Krishna
  • Nidhi Singh
  • K. Venkateswarlu
  • K. C. Hari Kumar
Article

Abstract

An Al-4Zn-2Mg alloy was subjected to cryorolling (CR) followed by short annealing. An average grain size of ~100 nm was achieved. Cryorolled samples showed large reduction in grain size due to suppression of dynamic recovery and absence of annihilation of dislocations, as compared to room temperature rolled samples. Further, the ultrafine-grained (UFG) Al-4Zn-2Mg alloy when subjected to natural aging showed an improved strength of ~413 MPa with ductility of ~25%, as compared to ~360 MPa and 22% ductility in peak aged condition of coarse-grained alloy. However, UFG alloy in peak aging condition, exhibited a relatively strength (~375 MPa) and 24% ductility combinations than the natural aging condition. The latter is attributed to dynamic precipitation and stored energy. In the present study, it is demonstrated that simultaneous improvement in strength as well as ductility can be achieved for the Al-4Zn-2Mg alloy through CR and controlled heat treatment combinations.

Keywords

aging Al-4Zn-2Mg alloy cryorolling secondary precipitation tensile behavior ultrafine-grain structure 

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Copyright information

© ASM International 2011

Authors and Affiliations

  • K. Gopala Krishna
    • 1
  • Nidhi Singh
    • 2
  • K. Venkateswarlu
    • 3
  • K. C. Hari Kumar
    • 4
  1. 1.National Metallurgical Laboratory (CSIR), Madras CentreChennaiIndia
  2. 2.National Physical Laboratory (CSIR)New DelhiIndia
  3. 3.National Aerospace Laboratory (CSIR)BangaloreIndia
  4. 4.Department of Metallurgical and Materials EngineeringIndian Institute of Technology, MadrasChennaiIndia

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