Abstract
Pulsed YAG laser was used for processing of silicon nitride ceramics. Analysis of surface layers of molten material remaining in plane making process was investigated by EPMA (Electron probe X-ray microanalyzer), ESCA (Electron spectroscopy for chemical analysis). The analyzed results indicate that the ejected molten material remaining around the processed region contains oxides of silicon, aluminum and yttrium, but is free from nitrogen. The oxide of silicon is produced by the following oxidation reaction : (1/3)Si3N4 + O2 → SiO2 + (2/3) N2. The main source of O2 in this reaction is atmospheric oxygen. The oxides of aluminum and yttrium added as sintering aids in silicon nitride ceramics are retained in the ejected molten materials.
