DETECTION OF DYNAMIC PROCESSES FOR LASER THERMOSTRENGTHENING OF THE MATERIAL SURFACE IN A REAL-TIME SCALEUNDER ILLUMINATION FROM LASER PLUME IN THE TRANSMISSION CHANNEL OF OPTICAL IMAGES VIA OPTICAL FIBER HARNESS USING A LASER BRIGHTNESS AMPLIFIER

Abstract

The article deals with model/test experiments on laser thermal hardening with the registration of the dynamics of the material surface modification in real time using a laser projection microscope (monitor) in the geometry of “pump-probe”. Hardening of materials by laser radiation, as well as dimensional processing compared to traditional methods is much more environmentally friendly because it happens very quickly and almost without emissions of harmful substances. And the possibility of observing the surface at the time of the hardening process can improve the quality of processed products. With the help of a laser projection microscope, it is possible to detect the moment of appearance of the transition region arising from the interaction of laser radiation with matter, to monitor the dynamics of its expansion, to register the appearance of the thermal front, the melting front, oxide fronts which is relevant in the heat treatment processes. A large number of publications are devoted to such methods and their modifications which confirms the importance and effectiveness of diagnostic methods using laser projection microscope to study various dynamic processes in the interaction of laser radiation with matter. In this work, the modernization of laser projection microscope with inclusion in the probing channel of optical harness is carried out. The basic physical principles of the obtained system and the existing problems, as well as the prospects of their overcoming in various conditions of specific processes of laser thermal hardening, including the use of computer simulation to find the optimal optical circuits and modes, are revealed. Depth-of-field problems are discussed for the resulting image through an optical fiber/optical bundle when recording such dynamic processes and how to overcome them by choosing the appropriate optical scheme. The analysis is also carried out on the basis of computer modeling. These issues are important in the implementation of various thermal hardening regimes in experiments with single-and multi-beam radiation of a power laser affecting the object at the appropriate setting of the laser monitor in the probing channel.