Capabilities of vibration cutting at turning of hard-to-cut materials and built-up surfaces

Abstract

The article describes the results of vibration turning research for cutting the parts produced of austenitic steel of high ductility and strength, as well as for the machining of the surfaces reworked by the method of build-up welding. Lathe turning with a superposition of pendular-type harmonic vibrations to the cutting tool is one of the productive cutting methods of austenitic steel, from which parts of mining machines and equipment are made, and built-up surfaces as a result of repair of various parts of mining equipment. Selection of optimal amplitude-frequency parameters of cutting tool vibration allows to increase a period of tool material lifetime, to ensure constant process of chip breaking and helps to reduce a cutting force. When turning the materials with generation of pendular vibrations in cutting zone, some phenomena occur that are not observed during cutting without vibrations. Based on the results of tests of vibration turning the main facts were defined, which have the greatest influence on lifetime of cutting tools during cutting of austenitic class steels and built-up surfaces, it is expedient to consider: vibration velocity, vibration acceleration, vibrating influence energy dispersion. The concept of the vibration impact generalized function (VIGF) was introduced, which allows to describe mathematically three main factors of pendulum vibrations influence in the cutting zone. The equation of the mathematical model of vibration turning with VIGF is presented, which describes the dependence of the tool lifetime period on vibration parameters. The process of generation and breaking of the chips when turning the hard-to-cut materials is studied. The fields of temperature distribution in the cutting zone at turning are investigated.