Title: Modelling and optimisation of pulsed Nd: YAG laser cutting for average kerf taper and surface roughness during straight cutting of Ni-based superalloy thin sheet

Authors: Amit Sharma; Vinod Yadava

Addresses: Department of Mechanical Engineering, Motilal Nehru National Institute of Technology, Allahabad – 211004, Uttar Pradesh, India. ' Department of Mechanical Engineering, Motilal Nehru National Institute of Technology, Allahabad – 211004, Uttar Pradesh, India

Abstract: This paper presents a hybrid approach for optimising laser straight cutting of Ni-based superalloy thin sheet. The hybrid approach comprises of Taguchi methodology (TM) and response surface methodology (RSM). The input process parameters taken are oxygen pressure, pulse width, pulse frequency and cutting speed. The experimental output characteristics of interest in Ni-based superalloy thin sheet cutting are average kerf taper (T_a) and average surface roughness (R_a). First the values of optimum input parameters are obtained using TM only. The optimum value of input parameters so obtained are further used as central value in RSM. Further experiments are performed using central composite rotatable design (CCRD) matrix. Finally, second order response surface models are developed as well as optimum parameters are found using MINITAB software. A remarkable improvement in both the quality characteristics is found when hybrid approach is applied as compared to application of Taguchi approach only.

Keywords: laser beam cutting; LBC; Taguchi method; response surface methodology; RSM; CCRD; modelling; multi-objective optimisation; superalloy thin sheets; hybrid approach; machinability; laser cutting; kerf taper; surface roughness; nickel based superalloys; oxygen pressure; pulse width; pulse frequency; cutting speed; central composite rotatable design.

DOI: 10.1504/IJMMM.2012.046889

International Journal of Machining and Machinability of Materials, 2012 Vol.11 No.3, pp.223 - 243

Received: 23 Oct 2010
Accepted: 06 Mar 2011
Published online: 23 Aug 2014 *

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