Engineering of heat sources in laser precision machining

Abstract

Requirement towards the enhancement of the results of technological operations of laser processing, their transformation into precise technological operations is solved, in general, by the choice of optimal technological schemes of laser processing and characteristics of a tool that is formed from laser beam characteristics. The main goal of these attempts is to minimize portions of energy that destroys and removes the material from the cavity of element being formed utilizing ultra-short pulses of electro-magnetic energy with high intensity that can bring balance to the instability of technological process, manage it outcome and maintain the quality of processing. On the other hand, it leads to a decrease in the efficiency of technological operations of laser processing. For example, linear speed of laser cutting of stent with nanosecond pulses are used is within the range of 25 to 30 millimeters per minute, whereas in the case of microsecond pulses - the processing speed can reach up to 250 mm/min and slight striation of side surface of the cutting kerf could be eliminated by means of post processing. Since the process of material destruction at laser beam processing is of a thermal nature in terms of heat dissipation and its propagation into the body of the work piece (especially the metal one), it is possible to control and modify the absorption of radiation by the surface of the work piece, the spatial shape of the heat source and thermal an physical properties of the work piece. This paper discusses perspective solutions for the successful engineering of laser beam irradiation process.