Influence of Group IV and V Alloying Elements on the Microstructure Engineering and Deformation Behavior in Tantalum Carbides
Final rept. 1 Apr 2014-31 Mar 2015
ALABAMA UNIV TUSCALOOSA OFFICE OF SPONSORED PROGRAMS
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Tantalum carbides comprise a class of high and ultrahigh melting temperature materials with tremendous thermo-mechanical property potential. This program provided a fundamental series of studies to address how group IVB and VB metal carbide alloying brings about microstructural engineering with subsequent changes in thermo-mechanical behavior. The program employed a combined computational and experimental approach coupled through advanced analytical electron microscopy characterization to address this gap. Major findings include determination of an intrinsic stacking fault on the 111 planes in TaC that circumvents slip on 110, which is the dominant slip plane in HfC the competition of vacancy ordered and fault-forming phases with metal-enrichment in Ta-C the formation of vacancy ordered phase domains which are hypothesized to contribute to an anomalous rise in hardness for the group VB carbides absent in group IVB carbides and finally construction of a non-contact Lorentz force thermo-mechanically loading apparatus for testing these carbides above 3000 deg. C.
- Properties of Metals and Alloys