ABSTRACT
The results of WHITE-900 werea little bit different from the rest. Those of the other specimens were almost the same within the experimental error. As for the effect of the method of the peak determination, the results of the parabola approximation method were a little bit larger than those obtained using the FWHM method, except for the result of HIP. It should be ascertained in the future why WHITE-900, which was heat treated at a temperature less than that of sintering, showed a different result. It is known that a volume expansion of 4.6% takes place during the transformation from the tetragonal to the monoclinic at the temperature between 1173 K and 1273 K. The increase of the transformation due to the heat treatment at 1173 K for an hour after sintering might affect the elastic constants of WHITE-900.
