REALIZATION OF MELTED LAYERS WITH CO₂ LASER ON SINTERED CERAMICS

Abstract
The high sensitivity of ceramic materials to surface defects requires a surface treatment for minimizing this disadvantage or to reject their effects. The laser is a convenient and sometimes unique tool for investigating some of the methods of treatment or processing ceramics that may significantly improve their properties. The surface layers of materials were melted in air using a CO₂ laser radiation. As with most ceramic oxides, this radiation is efficiently absorbed and dissipated as thermal energy. The material used in this study was a sintered zirconia substrate (Mg - PSZ). The surface analysis by scanning electron microscopy indicated that fine and complex microstructures were developped in the surface of melted layers. The different phases in the substrates, before and after laser treatment, were detected by X-ray diffraction. Indentation technique has been applied to determine the hardness of melted layer and substrate.