Title: Optimisation of cut qualities during pulsed Nd:YAG laser cutting of SUPERNI 718 thin sheet for straight profile

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 reports the study of optimal process parameters for cutting Ni-based super alloy (SUPERNI 718) thin sheet along straight profile using Nd: YAG laser. The average kerf taper (Ta) and surface roughness (Ra) are considered as cut qualities and the essential process input parameters are identified as oxygen pressure, pulse width, pulse frequency and cutting speed for the present study. Taguchi methodology with L9 orthogonal array is employed for optimising both cut qualities individually and simultaneously. The optimisation results show a considerable improvement in the both qualities and the confirmatory experimental results have shown good agreement with the predicted results. It has also been found that the optimum condition of the cutting parameters for multi-performance characteristics varies with the different combinations of weighting factors. Based on the analysis, more weight has to be set for Ta to obtain the good quality cut. Finally, the results of multiple quality optimisation have been compared with the single quality optimisation results. From the comparison it has been found that Ra was increased by 30.34% in multiple quality optimisation however the Ta was same in both cases.

Keywords: laser manufacturing; SUPERNI 718 sheet; Taguchi methods; average kerf taper; average surface roughness; laser cutting; thin sheets; straight profiles; nickel alloys; superalloys; cut quality; oxygen pressure; pulse width; pulse frequency; cutting speed; orthogonal arrays.

DOI: 10.1504/IJMTM.2011.046763

International Journal of Manufacturing Technology and Management, 2011 Vol.24 No.1/2/3/4, pp.108 - 123

Available online: 04 May 2012 *

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