LASER MACHINING OF CARBON FIBER REINFORCED POLYMERIC (CFRP) COMPOSITE

Abstract

Carbon Fiber Reinforced Polymeric (CFRP) Composite are of great interest for several high strength to weight ratio Engineering Material Applications as a substitute to metals in Aerospace, Marine, Automotive, Military, Sports and Energy Industry due to properties like high strength to weight ratio ,higher stiffness, abrasion ,very high corrosion and wear resistance .Composite materials have relatively high cost and manufacturing process is complex as compared to metals .The anisotropic and heterogeneous properties of composites makes its machining very challenge. Conventional Machining of composites have several draw backs e.g. force input, handling of auxiliaries ,high tooling cost ,Tool wear, Poor machine quality ,Low Productivity in addition to these tool size and geometry makes conventional machining less attractive . So Laser is a potential alternative for machining and joining of composites due to wear free, fast and contactless processing .Laser involves the Thermal energy process and it does not depend upon the strength and hardness of the work piece A parametric study of laser Cutting was conducted on 1 mm,1.5 mm CFRP sheet using 20 W Fiber pulsed laser and 5 mm using Nd:YAG 500 W pulsed Laser . The control parameters examined were Laser power, pulse width and pulse frequency in 20 W fiber laser while in Nd: YAG pulsed laser Current, Pulse Width and Pulse Frequency were parameters. The output Experimental results were compared against Heat Affected zone (HAZ) and kerf Width .The large difference in thermo-mechanical properties of carbon Fibre and epoxy resin make the laser machining very challenging. The aim of the research is to analyze the effect of process parameters on cutting quality characteristics using Full Factorial Design of Experiments. The ANOVA (Analysis of Variance) was used to analyze the results and to determine the significance of process parameters on cutting quality characteristics. It has been found from the results that kerf width is wide at top surface while HAZ is more noticeable at bottom due to heat accumulation in the material .The main and interaction effects on HAZ and kerf width are analyzed.