International Journal For Technological Research In Engineering ISSN (Online): 2347 - 4718 National Conference on Importance of Inter-disciplinary Studies in Higher Education in the areas of Engineering, Science, Management and Humanities (February – 2018) www.ijtre.com Copyright 2018.All rights reserved. 55 OPTIMIZATION OF PROCESS PARAMETERS OF FIBRE LASER ON THE CUTTING QUALITY OF STAINLESS STEEL-304 BY USING FULL FACTORIAL DESIGN OF EXPERIMENT APPROACH Darshan R. Shah 1 , Dheeraj Soni 2 1 Rersearch Scholar, 2 Asst. Prof. & Head, Department of Mechanical Engineering, SS College of Engineering, Udaipur, Rajasthan, India. Abstract: Fibre laser technique is a latest technology in laser cutting. This technique is also available at different power levels and very narrow spot size. Stainless Steel is widely used in various industries throughout the world for producing a number of machinery parts. It requires higher power due to the refractivity & hardness. Therefore, fibre lasers are used for cutting Stainless Steel specially. The aim of this work is to study the influence of process parameters like: cutting power, laser power, assist gas pressure on cutting quality like depth of cut and surface roughness. Full factorial Design of Experiment approach will be applied to find the number of experiments runs to perform on the fibre laser machines. A regression analysis was to find the connection between process parameters and response. Also the interaction between process parameters and its effect on response was done by using ANOVA analysis. Keywords: Cutting Speed, Laser Power, Laser Cutting, Stand-off Distance (SOD), Surface Roughness, Assist Gas Pressure, Design of Experiment (DOE). I. INTRODUCTION Laser cutting operation is a thermal based non-contact process that is capable of cutting complex contour on material with high degree of precision and accuracy. It involves process of heating, melting and evaporation of material in a small well defined area and capable of cutting almost all materials. The laser cutting process has developed significantly over the last few decades & has become daily routine in sheet metal fabrication process as a result of attractive cutting velocities, processing flexibility, excellent cutting quality and wide spread application.[1] The first working laser was invented in May 1960 at the Hughes Research Laboratories by T. H. Maiman when he successfully applied an optical pumping technique to an active material (ruby crystal) resulting in the attainment of stimulated optical emission.[2] In Laser cutting process, heating, melting & evaporation is done. Laser can also be defined as Light Amplification by Simulated Emission of Radiation. In industries laser is used as unconventional process for cutting, melting, & welding purposes. Laser has a broad range of applications in various manufacturing and other industries. Laser is used to cut various materials like rubber, ceramic, wood, stainless steel, & many more materials. [3] II. LASER CUTTING TECHNIQUE There are a number of LASER techniques are available. The techniques are classified as: 1) CO2 Laser 2) Nd:YAG Laser 3) Fibre Laser 2.1 CO2 Laser: Because of their ability to produce very high power with relative efficiency, carbon dioxide (CO2) lasers are used essentially for materials-processing applications. The standard output of these lasers is at 10.6 mm, and output power can range from less than 1.5W to 10 kW. Unlike atomic lasers, CO2 lasers work with molecular passage which lie at low enough energy levels that they can be populated thermally, and an increase in the gas temperature, caused by the ejection, will cause a decrease in the inversion level, reducing output power. There are many types of CO2 lasers are available. High-power pulsed lasers typically use a transverse gas flow with fans which move the gas through a laminar-flow discharge territory, into a cooling territory, and back again. Low-power lasers most often use waveguide structures, coupled with radio-frequency excitation, to produce small & compact systems. It uses a wavelength of infrared light produced is 10.6 μm. Furthermore, whereas the long CO2 wavelength removes material thermally through boiling of material, the CO2 lasers with wavelengths near 200 nm remove material through ablation without any thermal damage to the surrounding material. 2.2 Nd:YAG Laser: The neodumium (nd) & neodymium yttrium aluminium gamet (Nd:YAG) lasers are identical in style & differ in application. Nd:YAG laser is differ in that the wave length of infrared light produced is 1.06 μm. It uses crystalline material for lasing operation. The Nd:YAG lasers are commercially available in power up to 5 kw. 2.3 Fibre Laser: Fibre laser is seen as an efficient reliable & compact solution for micro machining which heat affected zone, kerf width & dross could be diminished to a minimum. This because its important advantages as the mixture of high beam power with high beam quality, higher efficiency, small spot sizes & less maintenance. Industrial users of laser technology have