| 摘要 |
PURPOSE:To maintain light transmitting properties and prolong the life by forming a corrosion-resistant film composed of a specific oxide on the surface requiring the corrosion resistance of a light transmitting base material. CONSTITUTION:These light transmitting ceramics are obtained by forming a corrosion-resistant film composed of an oxide having a negative standard Gibbs energy of formation and its greater absolute value than the standard Gibbs energy of formation of ceramics constituting the base material on one surface of the light transmitting base material. The oxide has the negative standard Gibbs energy of formation and its absolute value is >=1581.9kJ/mol. One or plural kinds of Ce2O3, Dy2O3, Eu2O3, Gd2O3, Ho2O3, La2O3, Lu2O3, Nd2O3, Pr2O3, Sc2O3, Sm2O3, Y2O3, Yb2O3, Tb2O3 and Ta2O3 are used as the oxide. This figure is an enlarged sectional view of the light transmitting ceramics. A light emitting tube 2 is constituted of a light transmitting base material 11 composed of Al2O3 and a corrosion-resistant film 12, integrally formed in the interior thereof and having <=100mum thickness and the boundary part is a gradient layer 13 continuously changing the respective composition ratios. |
