Avaliação do efeito do revestimento TiN em ferramenta de metal duro no torneamento de aço 1050

Abstract

This work presents an analysis of the machinability of the AISI 1050 Carbon Steel machining, varying the cutting speed, in carbide tools with and without TiN coating, advance of 0.1 mm/rev, depth of cut 2.0 mm and travel of advance 15 mm. The average force, acquired with Piezoeletric platform Dynamometer, was higher with the TiN coated tool in most of the graph. The degree of repression was predominantly higher for the uncoated tool. The average roughness of the workpiece machined with the uncoated tool is greater than with the coated tool, acquired with a digital rugosimeter. The graphs and images made with Scanning Electron Microscope showed that in the 30 m/min uncoated test and the 40 m/min coated test there was an incidence of built up edge. At the speed of 60 m/min for the coated tool still had built up edge. However, at 60 m/min without coating there was no more built up edge. Thus, with the coating, the built up edge was more present than uncoated. Marks due to machine vibration and tool wear were found on the top surface images of the chip sample of the cutting speed condition 60 m/min and tool without TiN coating.This sample was mounted with plastic putty, sanded, polished and attacked with 2% Nital acid and its analyzed microstructure. It was concluded that the coated tool, although presenting more built up edge, presented more advantages in the process, because the machined part had superior surface finish.