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 without concomitant development of crack-inducing thermal gradients has been developed for the localized surface modification and repair of small manufacturing defects in brittle and low-thermal-conductivity solids. Heat transfer and mechanical modeling of the process have allowed development of specialized heating algorithms. Low-positive-expansion frits with low glass transition temperature also have been developed that enable rapid treatment of small areas without the generation of parasitic critical stresses.