WETTABILITY, SURFACE-TENSION, AND REACTIVITY OF THE MOLTEN MANGANESE ZIRCONIA-YTTRIA CERAMIC SYSTEM/

A basic research study for improvement of plasma-sprayed zirconia coat ings has been conducted. The contact angle and surface tension of the molten manganese/zirconia-yttria ceramic system were measured at 1573 K by the sessile drop method, suggesting that molten manganese would s pontaneously infiltrate open pores in zirconia coatings. Structure and elementary composition development of zirconia ceramics caused by rea ction with manganese were examined by using scanning electron microsco py (SEM), an electron probe microanalyzer (EPMA), and an X-ray diffrac tometer (XRD). Manganese not only stabilized cubic zirconia but also c ontributed to the growth and volume increase of zirconia particles. In this article, the mechanism of making zirconia coatings dense with ma nganese is discussed based on the results of experiments.