Use of high-power diode lasers for hardening and thermal conduction welding of metals

The developments in the sphere of semiconductors have also led to a new generation of laser beam sources for processing methods for materials. The first High Power Diode Lasers (HDL) give very promising perspectives for the production technology due to their size, efficiency and the future trend in prices. Up until now there is no systematic knowledge concerning the technology of metalworking using HDL. The essay shows the technological advantages of a 650 W-HDL for laser processing methods for materials. First of all the characteristics of the existent 650 W-HDL source are discussed: On the one hand the dependence of laser power and laser beam quality upon currency and focussing optics and on the other hand the short and long term operating behaviour of the plant. The results of experimental research of laser hardening of a heat-treatable steel and laser welding of a stainless steel are presented and discussed. In the experiments the influence of feed rate, beam spot geometry and -foc us on the process results (geometry, hardness, texture) are analysed. The quality inspection of hardness and weld results are described by metallographic analysis methods (hardness test, analysis of texture). The essay will be completed by an outlook over the possibilities of using HDL in manufacturing.