5 Advances in Production Engineering & Management ISSN 1854-6250 Volume 8 | Number 1 | March 2013 | pp 5–12 Journal home: apem-journal.org http://dx.doi.org/10.14743/apem2013.1.148 APEM journal Optimization of high-pressure jet assisted turning process by Taguchi method Sekulic, M. a , Kovac, P. a , Gostimirovic, M. a , Kramar, D. b,* a Faculty of Technical Sciences, University of Novi Sad, Trg Dositeja Obradovica 6, 21000 Novi Sad, Serbia b Faculty of Mechanical Engineering, University of Ljubljana, Askerceva 6, 1000 Ljubljana, Slovenia, EU A B S T R A C T A R T I C L E I N F O This paper outlines the Taguchi optimization methodology, which is applied to optimize cutting parameters in high-pressure jet assisted turning when ma- chining Inconel 718. Turning parameters evaluated are the diameter of the nozzle Dn, the pressure of the jet P, the cutting speed Vc, the feed rate f and the distance between the impact point of the jet and the cutting edge d. The ex- periments were conducted by using L27(3 13 ) orthogonal array as suggested by Taguchi. Signal-to-Noise (S/N) ratio and Analysis of Variance (ANOVA) are employed to analyze the effect of high-pressure jet assisted turning parame- ters on the main cutting force and surface roughness, in other words to find optimal levels of the process parameters. The study shows that the Taguchi method is suitable to solve the stated problem with minimum number of trials. © 2013 PEI, University of Maribor. All rights reserved. Keywords: High-pressure jet assisted turning Taguchi method Optimization *Corresponding author: davorin.kramar@fs.uni-lj.si (Kramar, D.) 1. Introduction All engineering materials are often divided into easy-to-machine or difficult-to-machine materi- als. There are new alloys especially difficult for machining, for instance, hardened steels, Cr-Co alloys, Ti-based, and Ni-based alloys. Cutting of nickel-based alloys is a topic of high interest for today’s industrial production and scientific research. Nickel-based alloys commonly used mate- rials in aerospace industry (engines), power production (power plant generators), environ- mental protection and waste management (flue gas desulphurization plants), chemical industry (cauldrons, heat exchangers, valves, pumps). According to [1], Inconel 718 is the most commonly employed nickel superalloy and represents 25–45 % of the annual volume production. Nickel-based alloys are well known to yield a very poor machining performance. Different assistance methods have been developed to replace the "conventional cutting process". One of them is high-pressure jet assisted turning (HPJA), which aims at upgrading conventional ma- chining using the thermal and mechanical properties of high-pressure jet of water or emulsion directed into cutting zone [2]. High pressure jet assisted turning (HPJA) presents an innovative method of lubricating and/or cooling the cutting zone during machining. This machining alter- native offer reduced costs, avoidance or reduction of health and environmentally hazardous. Determination of optimal machining parameters in HPJA turning is continuous engineering task which goals are to reduce the production costs and to achieve the desired product quality. Following modern production requests and technologic-economic analysis of processing opera- tions, during the designing process, it is necessary to determine optimal cutting parameters in order to achieve minimal expenses or minimal production time [3].