22nd Congress of International Council of the Aeronautical Sciences, Harrogate, UK, 28 August - 1st September, 2000
Paper ICAS 2000-4.5.3

DEFORMATION INHOMOGENEITY IN A SINGLE CRYSTAL NICKEL BASE SUPERALLOY

J. H. Zhang, J. L. Liu, T. J. Jin, Y. B. Xu, Z. Q. Hu
Institute of Metal Research, Chinese Academy of Science, PRC

Keywords: deformation, plastic inhomogeneity, superalloy

The plastic inhomogeneity has been investigated in DD8 single crystal nickel-base superalloy. It has been found that this phenomenon occurs just after the alloy is yielded on the stress-strain curve during extension and compression at a certain strainrate under the certain temperature ranges. When the plastic inhomogeneity (serration) on the stress-strain curve occurs, it can burst on a sound with “ Ping-Pang ”, and accompanies a catastrophic drop in yield strength of the alloy. This kind of plastic inhomogeneity in the alloy can be removed by a new heat treatment.

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