Laser Laboratory - 108 EES
Professor Segall and his group are currently investigating dual-beam laser-machining methods that hold the promise of improving both machining quality and throughput by controlling and healing the micro- to macro-scale damage inherent to the practice.
In order to achieve these goals, a new process of simultaneously scoring (prescoring) the surface to help control the path and surface of the final fracture was developed with support from the National Science Foundation; while the use of dual lasers is certainly a new innovation, creating a shallow score-line along a desired fracture path is a well-proven and economical way of ensuring the quality and direction of a cut as demonstrated by stone and tile masons for centuries.
In a new twist however, the dual-laser system will also be used to “actively stress” the fracture prone region into a localized state of thermoelastic compression, thus helping to offset the unavoidable tensile-stresses that are ultimately the cause of damage and fracture.
laser machining and evolving groove
morphology.
Studies have also been recently started on the intriguing use of a second beam to heal the micro-crack damage after the ceramic has been machined; in this case, a reduced-power beam will be used to partially melt the freshly cut surface in a controlled fashion to fuse any micro-cracks caused by the main cutting beam. For all of the dual-beam techniques just discussed, existing systems can be readily adapted by using commercially available beam-splitters and available laser power. Hence, the quality of the laser cut can be readily improved without added manufacturing steps or high costs.