Features of Zr-rich corner of the Zr-N-O ternary system by controlled low-pressure oxidation and thermodynamic analysis

Lam, Do Van*; Do, Thi Mai Dung*; Ogawa, Toru

In order to clarify the Zr-rich corner of the Zr-N-O ternary system, a series of nitridation and controlled low-pressure oxidation heatings were made on zirconium metal. Low-partial pressures of oxygen were obtained by using a redox couple of either Mo/MoO or CuO/CuO. The heated samples were characterized by X-ray diffraction (XRD), optical microscopy and electron probe micro analysis (EPMA). Experimental results were coupled with a preliminary thermodynamic analysis with a sublattice formalism to draw a provisional ternary isotherm at 1373 K.