Detekce trvanlivosti keramických řezných nástrojů pomocí integrovaných odporových vrstev

Abstract

The presented dissertation thesis follow up methodology of monitoring the wear of inserts with built - up impedance layer. The Impedance layer is built - up on an exchangeable cutting edge compounded of nitride ceramics. The tool (cutting insert) is designed in a specific way, so each cutting edge creates a close conductive electric circuit. The electric resistance is measured and recorded during the machining process thanks to a special tool holder and other devices. The tool wear is measured after each cut. Measuring is realized on a PC with measuring software and it is based on photos done by a microscope. Experiments were performed at longitudinal turning on four different semi-finished products of the same material of spheroidal graphite cast iron. The 3 experiments with various cutting conditions were done on each semi-finished product. The temperature on the insert tip was measured additionally. The aim of the work is to investigate the relationship between a tool wear curve and an electric resistance curve. And examining of the accompanying phenomena related to this issue. The practical part of the work contains a detailed description of the experiment together with a description of used machinery and equipment. There is a graphic representation of the measured values and their analysis. The final part summarizes the results and conclusions of science and the practice followed by recommendations for further research. The theoretical part is focused on the analysis of ceramic tool materials, their partition and basic description. The nitride ceramic production and features are described here. The types and mechanisms of tool wears, measuring methods and criteria for tool wear are described in further chapters. The methods of tool diagnostic are mentioned as well. There is also mentioned knowledge of foreign publications dealing with the diagnosis of a cutting tool using resistive layers in turning and milling.