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Mechanical Properties of Diverse High-Temperature Compounds–Thermal Variation of Microhardness and Crack Formation

Published online by Cambridge University Press:  26 February 2011

Robert L. Fleischer*
Affiliation:
General Electric Corporate Research and Development, Schenectady, NY 12301
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Abstract

Microhardness vs temperature and elastic moduli have been measured for a suite of intermetallic compounds that melt above 1400°C. Binary intermetallics were selected to represent a variety of crystal structures and yet have optimal combinations of high melting temperature (Tm) and low specific gravity. Some deliberately two-phase alloys were prepared in which one phase is a terminal-phase metal and the other an intermetallic compound.

Binary compounds can be described by two patterns. In those where plasticity is difficult, hardness decreased slowly with temperature up to Tm/2, the decrease being no more than that normally shown by the elastic moduli. In those compounds where single crystal plasticity is known (or at least plausible), microhardness decreases more rapidly than do elastic moduli, presumably due to thermally activated slip.

Type
Research Article
Copyright
Copyright © Materials Research Society 1989

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References

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