Magnetic Abrasive Finishing Of Cutting Tools For Machining Of Titanium Alloys

CIRP Annals - Manufacturing Technology 61 (2012) 311–314 Contents lists available at SciVerse ScienceDirect CIRP Annals - Manufacturing Technology jou rnal homep age : ht t p: // ees .e lse vi er . com /ci r p/ def a ult . asp Magnetic abrasive finishing of cutting tools for machining of titanium alloys Hitomi Yamaguchi a,*, Anil K. Srivastava (3)b, Michael A. Tan a, Raul E. Riveros a, Fukuo Hashimoto (1)c a b c Department of Mechanical and Aerospace Engineering, University of Florida, 226 MAE-B, Gainesville, FL, USA TechSolve Inc., Cincinnati, OH, USA Technology Center, The Timken Company, OH, USA A R T I C L E I N F O A B S T R A C T Keywords: Cutting tool Finishing Wear Uncoated carbide tool surfaces are conditioned using magnetic abrasive finishing (MAF) to improve the tool wear characteristics by reducing friction between the tool and chip. The configuration of the magnetic particle chains that drive the abrasives plays an important role in surface finishing with minimal damage to the tool cutting edges. Roughnesses of less than 25 nm Ra on the flank and nose and less than 50 nm Ra on the rake can be achieved. In turning of Ti–6Al–4V alloy rods (at 100 m/min cutting speed), MAF-processed tools exhibited tool lives of up to twice as long as unprocessed tools. ß 2012 CIRP. 1. Introduction The significance of titanium alloys is found in their light weight, high strength-to-weight ratio, excellent corrosion resistance, good biocompatibility, and relatively low coefficient of thermal expansion [1]. Moreover, titanium alloys can exhibit the same advantages even at elevated temperatures. These attributes lead to a wide range of applications, especially in aerospace engines and airframe components [2]. On the other hand, some undesirable characteristics – such as low thermal conductivity and a chemical affinity with cutting tool materials and coatings – accelerate tool wear and create difficulties in machining titanium alloys [3]. Various approaches used to improve the machinability of titanium alloys and the life of cutting tools include development and control of tool materials and geometries, coating methods and materials, process parameters, and coolant use [4–7]. Although technologies are ever improving, an innovative method to achieve a significant extension of the tool life during high-speed machining is highly desired. In machining, a cutting tool mainly fails due to wear, which is typically attributed to high temperature at the tool–chip interface. Reducing friction between the tool and chip to encourage smooth chip flow can be a promising method to reduce the tool–chip interface temperature and thus slow down the tool wear rate. It has been shown that structuring or