Title: Analysis of cutting forces and surface roughness in hard turning of AISI 4340 using multilayer coated carbide tool

Authors: S. Basavarajappa; R. Suresh; V.N. Gaitonde; G.L. Samuel

Addresses: Department of Mechanical Engineering, University B.D.T. College of Engineering, Davangere-577004, Karnataka, India ' Department of Mechanical Engineering, Alliance College of Engineering and Design, Alliance University, Bangalore-562106, Karnataka, India ' Department of Industrial and Production Engineering, B.V.B. College of Engineering and Technology, Hubli-580 031, Karnataka, India ' Department of Mechanical Engineering, Indian Institute Technology Madras, Chennai-600 036, Tamil Nadu, India

Abstract: The effects of cutting speed, feed rate and depth of cut on machinability aspects such as cutting force and surface roughness during hard turning of AISI 4340 steel using chemical vapour deposited (MT CVD) multilayer (TiN/MT-TiCN/Al₂O₃) coated carbide tool were experimentally investigated. The experimental results revealed that the thrust force is more dominant than the cutting force and feed force. The thrust force increases with increased depth of cut and feed rate, while it decreases with increased cutting speed. The surface finish of the hardened component improved when the cutting speed has been elevated, whereas the surface quality deteriorated with increased feed rate. The worn parts of the cutting tool and machined surface were examined under scanning electron microscope (SEM). The flank and crater faces were severely grooved by the hard particles of work piece material exhibiting abrasive wear phenomenon. Intermittently, chipping on the tool rake face as well as catastrophic failure were also observed in continuous machining. Chip morphology study indicates the formation of saw toothed type serrated chips operating under several cutting conditions.

Keywords: hard turning; coated carbide tools; cutting forces; surface roughness; surface quality; cutting speed; feed rate; depth of cut; machinability; AISI 4340 steel; abrasive wear; chipping; tool failure; chip morphology; chip formation; tool wear.

DOI: 10.1504/IJMMM.2014.064687

International Journal of Machining and Machinability of Materials, 2014 Vol.16 No.2, pp.169 - 185

Received: 09 Aug 2013
Accepted: 22 Mar 2014
Published online: 10 Sep 2014 *

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