Loading...

Ductility Enhancement of Accumulative Roll bonded Aluminum Sheet by Developing a Bimodal Grain Size Distribution

Kourosh Khalili | 2014

702 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 46707 (07)
  4. University: Sharif University of Technology
  5. Department: Materials Science and Engineering
  6. Advisor(s): Seyyed Reyhani, Morteza; Akbarzadeh Changiz, Abbas
  7. Abstract:
  8. The goal of this project is production of composite laminated sheetswith bimodal microstructure using ARB process. It is planned to produce a laminated sheet having bimodal grain size distribution in microstructure to increase the formability while maintaining the strength. Two different aluminum alloys including AA 1050 and AA5083 were ARB processed up to 9 cycles, Then the ARB samples were annealed under controlled temperatures and times. Due to structural differences like stacking fault energy,stored cold work energy and solute atoms concentration, annealing ofThese two alloys lead to different recrystallized grain sizes. In order to evaluate the recovery and recrystallization behavior of these alloys,thermal analysis (DSC) and hardness tests were conducted and the microstructure of sheets werecharacterize by opical microscopy.
    Microscopic characterization shows that the layers in 5083 alloy start to neck and fracture after 5th cycle of ARB, which turns the macrostructure from laminar composite to particle composite. DSC analysis shows thatoccurance of recovery and recrystallization in both 1050 and 5083 alloy microstructure helps to find the best annealing conditions as 350 ̊C for 20 minute. Final microstructure of 8 cycle ARBed and subsequently annealed samples consist of a homogenous distribution of fine grain size 5083 alloy in a coarse grain size matrix of 1050 alloy.
    Tesnsile test results indicates that the increasing the ARB cycles in subsequently annealed samples withmore fine and homogenousmicrostructure lead to higher UTS, while maintaining high percent of total elongation
  9. Keywords:
  10. Accumulative Roll Bonding (ARB) ; Aluminum Blank ; High Strength ; High Ductility ; Bimodal Grain Size ; Improve Ductility

 Digital Object List

 Bookmark

No TOC