| Abstract |
| In order to clarify the effect of Nb addition on the deformation properties of a sintered TiC matrix solid solution at high temperature, we made a study using a compression test at temperatures from 983 to 2223 K and at the strain rates from 2.1×10-4 to 5.2×10-2/s. Further, X-ray photoelectron spectroscopic (XPS) measurements were carried out. We found that solid solution hardening in the Nb added TiC matrix was smaller than that in a Mo added TiC matrix solid solution, though the size misfit parameter in the Nb added TiC matrix was larger than that in Mo added TiC matrix, which had an extremely high strength, being 15 to 20 times higher than TiC. The work softening phenomenon was for the first time clearly observed in the present investigation. This phenomenon shows the presence of a frictional resistance to dislocation motion. The deformation equation of state at the yield stress can be expressed by εp=A (σy/G)mexp (-Q/RT) where m=9 and Q=112 kJ/mol in the low temperature range at and below 1083 K and where m=10 and Q=343 kJ/mol in the high temperature range at and above 1873 K. The XPS measurement suggests that dislocationsolution atom interaction resulting from a change in electronic structure should be effective for solution hardening. (Received April 10, 2014) |
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| Key Words |
| composites, sintering, mechanical properties, compression test, solid solution |
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