In this paper first results on 3d laser cutting of glasses as a technology for rapid tooling, obtained at the laser institute of the University of Applied Sciences Mitt-weida, are presented. The investigations were carried out with a short pulse Nd:YVO4 slab laser from Edge-wave (Aachen) and a high repetition rate femtosecond laser of Clark-MXR Inc. Michigan. In the experiments the laser beam was focussed onto the sample with both a stationary aspheric lens and a laser scanner with an f-theta-objective combined with a high precision xyz-axis stage.
The technique utilizes nonlinear absorption effects to induce local heating, followed by stress generation and finally micro defect formation inside the transparent bulk material. Several side effects have to be considered in machining of transparent materials, for example, nonlinear processes like self focussing and the focal shift.
In the beginning for various glasses the dependence of the micro defect formation on the process parameters were investigated in detail - possibilities and limits are discussed. The development of strategies of applicable arrangements of micro defects to produce fracture lines, planes and shells enclosing the required component are object of the investigations in order to produce 3d parts. These components created with the presented technology are consisting of bulk material - the key benefit in comparison to laser sintered parts.