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Fracture characteristics of austempered spheroidal graphite aluminum cast irons

  • Masoud Zandira
  • Seyyed Mohammad Ali Boutorabi
Article

Abstract

The fracture characteristics of austempered spheroidal graphite aluminum cast iron had been investigated. The chemical content of the alloy was C3.2, Al2.2, Ni0.8 and Mg0.05 (in mass percent, %). Impact test samples were produced from keel blocks cast in CO2 molding process. The oversized impact samples were austenitized at 850 and 950 °C for 2h followed by austempering at 300 and 400 °C for 30, 60, 120 and 180 min. The austempered samples were machined and tested at room temperature. The impact strength values for those samples austempered at 400 ’C varied between 90 and 110 J. Lower bainitic structures showed impact strength values of 22 to 50 J. The fractures of the samples were examined using SEM. The results showed that the upper bainitic fracture revealed a honey Comb-like topography, which confirmed the ductile fracture behavior. The lower bainitic fractures of those samples austempered for short times revealed brittle fracture.

Key words

austempering fracture characteristic aluminum cast iron 

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References

  1. [1]
    Forrest R D. Austempered Ductile Iron for Both Strength and Toughness [J]. Machine Design, 1985, 57(22): 95.Google Scholar
  2. [2]
    Crane F A A, Charls J A. Selection and Use of Engineering Materials [M]. London: Butterworth, 1984.Google Scholar
  3. [3]
    Dorazil E, Barta B, Munsterova E. High Strength Bainitic Ductile Cast Iron [J]. AFS International Cast Metals Journal, 1982, 7(2): 52.Google Scholar
  4. [4]
    ASM. Metals Handbook [M]. 8th ed. Metals Park: ASM, 1974.Google Scholar
  5. [5]
    Jolley G, Gilbert G N J. Segragation in Nodular Iron and Its Influence on Mechanical Properties [J]. The British Foundryman, 1967, 60(3): 79.Google Scholar
  6. [6]
    Al-Biedhany FAT. Transformation Kinetics, Structure and Mechanical Properties of Unalloyed and Ni-Mo Alloyed Austempered Spheroidal Graphite Cast Irons [D]. Birmingham: The University of Birmingham, 1984.Google Scholar
  7. [7]
    Boutorabi S M A, Young J M, Kondic V. Ductile Aluminum Cast Iron [J]. Cast Metals, 1992, 5(3): 122.CrossRefGoogle Scholar
  8. [8]
    Boutorabi S M A, Young J M, Kondic V. Austempering Kinetics of Spheroidal Graphite Aluminum Cast Iron [J]. International Journal of Engineering, 1995, 6(2a): 45.Google Scholar
  9. [9]
    Boutorabi S M A. The Austempering Kinetics, Microstructure and Mechanical Properties of Spheroidal Graphite Unalloyed Aluminum Cast Iron [D]. Brimingham: University of Brimingham, 1991.Google Scholar
  10. [10]
    Rao P P, Putatunada S K. Investigations on the Fracture Toughness of Austempered Ductile Irons Austenitized at Different Temperatures [J]. Materilas Science and Engineering Journal, 2003, 349: 136.CrossRefGoogle Scholar
  11. [11]
    Eric O, Sidjanin L, Miskovic Z, et al. Microstructure and Toughness of CuNiMo Austempered Ductile Iron [J]. Materials Letters Journal, 2004, 58: 2707.CrossRefGoogle Scholar
  12. [12]
    Kim Y J, Shin H, Park H, et al. Investigation Into Mechanical Properties of Austempered Ductile Cast Iron (ADD in Accordance With Austempering Temperature [J]. Materials Letters Journal, 2008, 62: 357.CrossRefGoogle Scholar
  13. [13]
    Sidjanin L, Smallman R E, Boutorabi S M. Microstructure and Fracture of Aluminium Austempered Ductile Iron Investigated Using Electron Microscopy [J]. Materials Science and Technology, 1994, 10: 711.CrossRefGoogle Scholar
  14. [14]
    Sidjanin L, Smallman R, Boutorabi S M A, et al. The Influence of Microstructure on the Mechanical Properties and Fracture Toughness of ADI [C] //Engineering Materials Advisory Serviced LTD. Reliability and Structural Integrity of Advanced Materials. Birmingham: EMAS Publication, 1993: 61.Google Scholar

Copyright information

© China Iron and Steel Research Institute Group 2010

Authors and Affiliations

  • Masoud Zandira
    • 1
  • Seyyed Mohammad Ali Boutorabi
    • 2
  1. 1.Department of Materials and Manufacturing TechnologyChalmers University of TechnologyGöteborgSweden
  2. 2.Center of Excellence for Advanced MaterialsIran University of Science and TechnologyTehranIran

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