ВЛИЯНИЕ РЕЖИМОВ ЛАЗЕРНОЙ МОДИФИКАЦИИ НА СТРУКТУРУ, СВОЙСТВА И ИЗНОСОСТОЙКОСТЬ МЕЛКОРАЗМЕРНОГО ИНСТРУМЕНТА ИЗ БЫСТРОРЕЖУЩЕЙ СТАЛИ Р6М5

Abstract

The paper considers the issue of wear resistance improvement of small-sized cutting tools. One of the advanced ways to solve this problem is the heat treatment using the highly concentrated energy flows created by laser beam. Modern fiber optic lasers combine high power density of laser radiation with the possibility of laser beam delivery to the most hard-to-reach treated areas by using optic fiber. The study and forecasting of the properties and the structure of a modified zone are the most important elements of technological process preparing and allow selecting optimal modes of laser treatment. The paper gives the results of experimental study of the influence of laser modification parameters on the state and properties of the surface layer of the high-speed R6M5 steel samples. The authors obtained the dependences of heat-affected zone depth and width on the laser radiation power, measured the microhardness of various areas of treated surface and studied in details the structure obtained for various laser modification modes. The study revealed the increase in microhardness resulting from the fiber optic laser modification during the quasi-continuous operation and set the boundary between the modes of laser modification with flashing and without it for R6M5 tool steel. As the practical application of the results obtained, the authors carried out the evaluation of small-sized tools wear resistance according to the suggested modes and determined the laser modification modes allowing the increase of durability of small diameter twist drills in 5 and more times. Test results demonstrate the unavailability of some relevant modes for the tool working surfaces modification due to the extremely gross wear of the processed surface and the cutting edge damage within the cutting process.