Process modeling and parameter optimization using radial basis function neural network and genetic algorithm for laser welding of dissimilar materials

Abstract

The welded joints of dissimilar materials have been widely used in automotive, ship and space industries. The joint quality is often evaluated by weld seam geometry, microstructures and mechanical properties. To obtain the desired weld seam geometry and improve the quality of welded joints, this paper proposes a process modeling and parameter optimization method to obtain the weld seam with minimum width and desired depth of penetration for laser butt welding of dissimilar materials. During the process, Taguchi experiments are conducted on the laser welding of the low carbon steel (Q235) and stainless steel (SUS301L-HT). The experimental results are used to develop the radial basis function neural network model, and the process parameters are optimized by genetic algorithm. The proposed method is validated by a confirmation experiment. Simultaneously, the microstructures and mechanical properties of the weld seam generated from optimal process parameters are further studied by optical microscopy and tensile strength test. Compared with the unoptimized weld seam, the welding defects are eliminated in the optimized weld seam and the mechanical properties are improved. The results show that the proposed method is effective and reliable for improving the quality of welded joints in practical production.

Research Progress on Characterization and Regulation of Forming Quality in Laser Joining of Metal and Polymer, and Development Trends of Lightweight Automotive Applications

“…The prediction ability of the model was good, the maximum relative error was 11.7%, and the accuracy was less than 12%. In addition, intelligent algorithms such as genetic algorithms, particle swarm optimization algorithms, and their improved algorithms are common methods for optimization of laser welding process parameter for dissimilar materials, and can be applied for the optimization of metal and polymer laser connections [218][219][220]. However, intelligent optimization algorithms depend on the accuracy of forming process parameters and the precision of the index relationship model.…”