Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/61397
Title: Superplasticity of friction stirred processed al 7075
Authors: Teo, Elizabeth Shu Hui
Keywords: DRNTU::Engineering::Mechanical engineering
Issue Date: 2014
Abstract: Superplastic forming has posed a strong industrial attraction due to its forming ability of large intricate shapes with sheet metal in one operation. This phenomenon is assisted by the fine grain size possessed by the material placed in an environment with an elevated temperature. The first objective for this experiment was to determine the optimal conditions (i.e. Temperature and strain rate) for which a post Friction Stir Process (FSP) Al 7075 would exhibit the greatest deformation. Samples were first cut into a dog-bone shape and subsequently an air sevo endurance testing system and thermostat were used to ensure temperature and initial strain rate constancy during the experiment period. The results showed a maximum deformation of 800% when placed in 425°C and 3x10-2 s-1 strain rate. The second objective for the experiment was to analyse the variation of microstructure in the material as it undergoes deformation. 5 samples were prepared for the Electron Backscattering Diffraction analysis: Pre-FSP, Post-FSP, after 5 minutes of preheating, at 50% of maximum elongation, at maximum elongation. Results indicated recrystallization as the dominant mechanism during the initial phases. However, upon the onset of strain, Grain Boudary Sliding became an active mechanism.
URI: http://hdl.handle.net/10356/61397
Schools: School of Mechanical and Aerospace Engineering 
Rights: Nanyang Technological University
Fulltext Permission: restricted
Fulltext Availability: With Fulltext
Appears in Collections:MAE Student Reports (FYP/IA/PA/PI)

Files in This Item:
File Description SizeFormat 
FYP report final.pdf
  Restricted Access
3.11 MBAdobe PDFView/Open

Page view(s)

314
Updated on Jul 23, 2024

Download(s)

12
Updated on Jul 23, 2024

Google ScholarTM

Check

Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.