Design, fabrication, and commissioning of apparatus for superplastic forming tests

  • Zemin Li

Student thesis: Master's Thesis

Abstract

Superplastic forming (SPF) is a near net shape manufacturing process in which a superplastic material sheet is pressed into a pre-heated die by means of gas pressure. In this process the deformed sheet could achieve very high plastic strains when the forming strain rate and temperature are appropriate. Magnesium alloy, the lightest engineering metal, closely meets the demand for reducing energy consumption in fields such as the automotive industry. However, its hexagonal close packed crystal structure leads to a low ductility at room temperature. On the other hand, the superplastic Mg alloys, such as AZ31B exhibit very large ductility at elevated temperatures. In this thesis, superplastic forming test apparatus are designed and fabricated for the study of the superplastic forming process of the magnesium alloy AZ31B. Detailed design process, testing methodology and corresponding testing results of these experiments were presented. Experiments were carried out to study the AZ31B alloy SPF characteristics, namely, high temperature tensile test, high pressure gas bulge forming test, and metallographic observation. Two SPF constitutive models were developed to describe the simulations were performed using the commercially available FEM software ABAQUS. The simulation results were compared against high temperature bulge forming test data. Results showed that the derived constitutive model does a reasonably good job in predicting the bulge forming process and could be used to describe the superplastic forming behavior of AZ31B alloy correctly.
Date of AwardDec 2016
Original languageAmerican English
SupervisorFiras Jarrar (Supervisor)

Keywords

  • Applied sciences
  • Experiment
  • Simulation
  • Superplastic forming
  • Mechanical engineering
  • 0548:Mechanical engineering

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