Investigations on tool wear stress and vibrations of uncoated and coated tool inserts in turning operation

Abstract

The machining process is essential in manufacturing industry Among all the machining processes turning is the broadest technique often used to remove the metal In this machining process metal removal rate is mainly influenced by the sharpness of cutting tools Due to the friction between the work piece and tool insert tool wear occurs After the wear takes place the efficiency of the machine is reduced and metal removal rate is reduced Hence it is essential to investigate the behaviour of tool wear under the machining It is found that the EN8 steel has wide applications in manufacturing of automobile components The wear of cutting tools are occurred often while machining Hence this research investigates the behaviour of tool inserts while machining of EN8 steels The objective of this research is to analyse the crater wear and flank wear characteristics of uncoated Silicon Carbide tool insert and Titanium Nitride coated tool insert while machining of EN8 steel cylindrical work piece In addition this research focuses on optimising the machining parameters feed rate depth of cut and spindle speed to reduce the crater wear flank wear vibrations and to increase the surface finish of work piece and cutting forces acting on the tool inserts The experiment is carried out in a lathe attached with a lathe tool dynamometer to measure the cutting forces acting on the tool insert while machining The EN8 cylindrical work piece is machined in lathe and the cutting forces are monitored in lathe tool dynamometer Before conducting the experiment design of experiments is carried out to reduce the experimental trials In which an L25 orthogonal array is obtained to carry out the experiment with 25 different combination of feed rate depth of cut and spindle speeds The wear occurred in uncoated Silicon Carbide tool insert and Titanium Nitride coated tool insert after the machining of EN8 steel cylindrical work piece is measured using tool makers microscope In general wear of tool affects the surface finish of the work pieceer