Fatigue Crack Propagation at Elevated Temperature in MAR-M002 Single Crystals

  • J. S. Crompton
  • J. W. Martin
Conference paper

Abstract

The effect of frequency on the rate of fatigue crack propagation in MAR M002 single crystals has been studied at a test temperature of 600°C. Centrally cracked plate specimens have been tested in air, and crack extension along { 100 } has been monitored by a DC potential drop method. da/dn versus ΔK curves are presented for test frequencies of 10 Hz, 1 Hz and 0.1 Hz. Near the fatigue threshold and near Kc, an increase in da/dn with increasing frequency is observed, but at intermediate ΔK the opposite effect is found. Scanning electron fractography revealed the important effect of ‘script’ carbide inclusions upon the crack extension process.

Keywords

Fatigue Nickel Carbide ECSC 

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Copyright information

© ECSC, EEC, EAEC, Brussels and Luxembourg 1982

Authors and Affiliations

  • J. S. Crompton
    • 1
  • J. W. Martin
    • 1
  1. 1.Department of Metallurgy and Science of MaterialsOxford UniversityUK

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