OPTIMIZATION OF ALUMINIUM LASER WELDING USING TAGUCHI AND EM METHODS

摘要

Effect of laser welding parameters such as power, outof-focus length, speed, diameter of feeding wire andfeeding speed on weld properties are studied. Theprocess parameters and their respective and interactiveeffects on the final responses have been investigatedsimultaneously by minimizing the number ofexperimental runs. The results, indicating theinterlateral relationship between laser processparameters and responses, have been used to optimizethe laser parameters, to predict the responses and toincrease the process robustness. Two millimetre thickplates of AA6061 were welded in fillet configurationusing a cw/Nd:YAG laser and AA5356 wire as thefiller metal. Two different experiment-designingmethods were used and compared to find the mostefficient way to optimize laser welding. The Taguchimethod that allows a multicriteria optimization, usingorthogonal arrays, was used to reduce the number oftrials necessary to cover the whole functional processparameters window. The same kind of optimizationwas then carried out with a combination of Taguchiand E.M. methods in a more interactive way allowing adynamic construction of the feasibility domainthroughout the data collection. The weld properties ofinterest were weld fillet size, penetration depth,concavity size and HAZ dimensions.