Micro machining of ceramics by pulsed Nd:YAG laser

Abstract

Several investigations of micro machining with CO2-lasers have been made within the last few years. The availability of pulsed Nd:YAG-laser systems with average power of > 500 W now offers the application of higher peak power, higher absorptivity and fiber transmission. Thus higher efficiency and flexibility can be expected.Laser machining is particularily interesting for hard materials like ceramics which resist to standard machining techniques. In this paper experiments performed with a 600 W pulsed Nd:YAG laser system and various ceramics (Al2O3, Si3N4, SiC) will be presented. Ablation rate and surface roughness for different pulse durations and focussing conditions will be given as a function of pulse energy and pulse power. Ablation rate as well as surface conditions within the ablation area are strongly influenced by the spatial distance per pulse and the spacing of the ablation traces. Limiting conditions relating to the travel speed of the processing machine will be given. The experimental results will be compared with theoretical considerations.The possibility of guiding the Nd:YAG-laser beam by a flexible fiber facilitates the intregration of the laser into machine tools. This concept now opens new ways in industrial ceramics machining. Concepts and results will be presented.Several investigations of micro machining with CO2-lasers have been made within the last few years. The availability of pulsed Nd:YAG-laser systems with average power of > 500 W now offers the application of higher peak power, higher absorptivity and fiber transmission. Thus higher efficiency and flexibility can be expected.Laser machining is particularily interesting for hard materials like ceramics which resist to standard machining techniques. In this paper experiments performed with a 600 W pulsed Nd:YAG laser system and various ceramics (Al2O3, Si3N4, SiC) will be presented. Ablation rate and surface roughness for different pulse durations and focussing conditions will be given as a function of pulse energy and pulse power. Ablation rate as well as surface conditions within the ablation area are strongly influenced by the spatial distance per pulse and the spacing of the ablation traces. Limiting conditions relating to the travel speed of the processing machine will be given. The experimental results...