Journal of Failure Analysis and Prevention

, Volume 16, Issue 1, pp 104–108 | Cite as

Failure Analysis of Tool Steel-Based Compaction Punch Used in Powder Metallurgy

  • Cassio Barbosa
  • Ibrahim de Cerqueira Abud
  • Tatiana Silva Barros
  • Sheyla Santana de Carvalho
Technical Article---Peer-Reviewed

Abstract

Powder metallurgy operations comprise the use of compaction dies and punches for transforming a mass of metallic powders into a porous block of aggregated particles with limited “green” strength. In this kind of application, dies and punches manufactured with tool steel are subjected to heavy loads to compress the metallic powders and form the block, which will be subjected to further consolidation operations such as sintering and/or some mechanical forming operation, such as forging or rolling. In general tool steels are high carbon and high alloyed steels designed for reaching high levels of mechanical strength, sufficient for his type of loading. However, defects on the surface of this material can lead to stress concentration, thus decreasing its fracture strength and eventually leading to failure. In this study, techniques such as optical and scanning electron microscopy are used to evaluate the possible causes of the failure of a compaction punch. The results indicated that machining grooves acted as stress concentrations which led to the premature fracture of the punch.

Keywords

Failure analysis Tool steel Fracture Microcopy 

Notes

Acknowledgments

The authors thank FAPERJ (research funding agency of the Rio de Janeiro state), Mauro de Melo Rodrigues, and Rafael de Abreu Vinhosa for preparing metallographic samples, the Laboratory of Inorganic Chemical Analysis (LAQUA) of INT for chemical composition analysis and CENANO/INT for SEM images.

References

  1. 1.
    ASM Handbook, Properties and Selection: Irons, Steels and High Perforance Alloys (ASM International, Materials Park, 2001), p. 1063Google Scholar
  2. 2.
    D. Casellas, J. Caro, S. Molas, J.M. Prado, I. Valls, Acta Mater. 55, 4277–4286 (2007)CrossRefGoogle Scholar
  3. 3.
    I. Picas, N. Cuadrado, D. Casellas, A. Goez, L. Llanes, Procedia Eng. 2, 1777–1785 (2010)CrossRefGoogle Scholar
  4. 4.
    K. Fukaura, Y. Yokoyama, D. Yokoi, N. Tsujii, Metall. Mater. Trans. A 35A, 1289–1300 (2004)CrossRefGoogle Scholar
  5. 5.
    E.M. Gonzalez, I. Picas, D. Casellas, J. Romeu, J. Acous. Emiss. 28, 163–169 (2010)Google Scholar
  6. 6.
    ASTM A681, Standard Specification for Tool Alloy Steels (2008)Google Scholar
  7. 7.
    A.J. McEvily, Metal Failures, Mechanisms, Analysis, Prevention (Wiley, New York, 2002), p. 324Google Scholar
  8. 8.
    R. Wouters, L. Froyen, Mater. Charact. 36, 357–364 (1996)CrossRefGoogle Scholar
  9. 9.
    A.S.M. Handbook, Failure Analysis and Prevention, vol. 11 (Materials Park, ASM International, 2004), p. 1164Google Scholar
  10. 10.
    ASM Handbook, Fractography, vol. 12 (ASM International, Materials Park, 2009), p. 517Google Scholar
  11. 11.
    ASM Handbook, Powder Metal Technologies and Applications (ASM International, Materials Park, 2011), p. 1146Google Scholar
  12. 12.
    ASTM E3, Standard Guide for Preparation of Metallographic Specimens (2011)Google Scholar
  13. 13.
    ASTM E407, Standard Practice for Microetching Metals and Alloys (2007)Google Scholar
  14. 14.
    G.F. Vander Voort, E.P. Manilova, J.R. Michael, G.M. Lucas, Microsc. Microanal. 10, 76–77 (2004)CrossRefGoogle Scholar
  15. 15.
    ISO 6507-1, Metallic Materials—Vickers Hardness Test—Part 1: Test Method (2005)Google Scholar
  16. 16.
    R. Hertzberg, Deformation and Fracture Mechanics of Engineering Materials, 4th edn. (Wiley, Hoboken, 1996), p. 786Google Scholar
  17. 17.
    D. Broek, Elementary Engineering Fracture Mechanics (Kluwer Academic Publishers, Dordrecht, 1986), p. 516CrossRefGoogle Scholar

Copyright information

© ASM International 2015

Authors and Affiliations

  • Cassio Barbosa
    • 1
  • Ibrahim de Cerqueira Abud
    • 1
  • Tatiana Silva Barros
    • 1
  • Sheyla Santana de Carvalho
    • 1
  1. 1.Instituto Nacional de Tecnologia (INT)Rio de JaneiroBrazil

Personalised recommendations