TRANSMISSION ELECTRON-MICROSCOPY OBSERVATIONS OF T'-PHASE AFTER LASER SEALING OF YTTRIA PARTIALLY-STABILIZED ZIRCONIA

In this study, specimens of 8.5 wt% yttria-partially stabilized zirconia plasma sprayed layers of thickness about 0.5 mm were remelted by carbon dioxide laser radiation at a power of 0.8-1.7 kW at a constant beam diameter of 5 mm and different traverse speeds. Overlapped tracks of approximately 1-% overlap were produced. The microstructure of the upper surface and transverse section of the layers were evaluated by SEM, energy dispersive X-ray spectroscopy for composition and x-ray diffraction for the phases present.