Localized surface modification of low-thermal-conductivity brittle solids

A new method utilizing temporal and spatial control of a CO2 laser beam to generate temperatures sufficient to melt and fuse a vitreous material witho ut concomitant development of crack-inducing thermal gradients has been dev eloped for the localized surface modification and repair of small manufactu ring defects in brittle and law-thermal-conductivity solids. Heat transfer and mechanical modeling of the process have allowed development of speciali zed heating algorithms. Low-positive-expansion frits with lour glass transi tion temperature also have been developed that enable rapid treatment of sm all areas without the generation of parasitic critical stresses.