1992 Volume 10 Issue 3 Pages 439-444
In CO2 laser cutting Si3N4 and A12O3 ceramics, temperature distribution was measured at various cutting speeds, assist gas pressures and laser powers, and cutting mechanism was discussed.
Results obtained are summarized as follows;
(a) At given cutting speed, the temperature at cutting front was constant from top to bottom surface. The temperature increased with increasing cutting speed, and was independent of laser power and assist gas pressure.
(b) From the slope of an Arrhenius plot, an activation energy was found to agree well with bond energy of Si-N and Al-O for Si3N4 and Al2O3, respectively, which shows that cutting speed is dominated by thermal decomposition rate of ceramics.
(c) High pressure N2 gas due to decomposition of Si3N4 blew the liquid Si layer off.
