Journal of Materials Science

, Volume 13, Issue 5, pp 1084–1092

The fracture characteristics of a superplastic single phase copper alloy

Authors

  • Shen -Ann Shei
    • Department of Materials ScienceUniversity of Southern California
  • Terence G. Langdon
    • Department of Materials ScienceUniversity of Southern California
Papers

DOI: 10.1007/BF00544704

Cite this article as:
Shei, S.-. & Langdon, T.G. J Mater Sci (1978) 13: 1084. doi:10.1007/BF00544704

Abstract

A superplastic single phase copper alloy exhibits a sigmoidal relationship between strain rate and stress at 823 K, dividing the behaviour into three regions. Maximum elongation to fracture (∼380%) occurs at intermediate strain rates at the lower end of region II, and there is a decrease in total elongation at both low (region I) and high (region III) strain rates. No necking is observed in regions I and II, and there is only very slight necking in region III. Internal cavities are formed at all strain rates, but the appearance of the cavities depends critically on the imposed strain rate. At high strain rates, the cavities are small and lie in strings parallel to the tensile axis; but as the strain rate is reduced the cavities become larger, more rounded, and essentially randomly distributed. The mode of failure is ductile rupture in region III, but void growth and interlinkage become increasingly important with decreasing strain rate.

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Copyright information

© Chapman and Hall Ltd 1978