| Popis: |
X-ray diffraction, TEM and SEM observations clearly show a phase demixion in the pseudo-binary system TiNx/ZrNy when x and y are near to 1. Various heat treatments show a total solubility between TiNx and ZrNy at high temperature: this solubility may be maintained, at room temperature, by quenching in conditions close to those used in the study of [delta]-TiNx in the binary system nitrogen-titanium. The microstructure of the demixed material presents characteristics that could be the result of a eutectoid transformation. The precise quantitative determination of the miscibility gap demands a great deal of complementary work, because of the experimental difficulties. The synthesis of massive nitrides, of sufficiently high purity, appears absolutely necessary to overcome the experimental limitation introduced by the synthesis processes from nitrides powders. All the results of further experiments will be published shortly, including the analysis of nitrogen by EELS and the observation of the interfaces by high resolution electron microscopy. |
