A study of process parameters during pulsed Nd:YAG laser notching of C70S6 fracture splitting connecting rods

This paper reports on the laser notching technology in C70S6 steel for fracture splitting connecting rod using a Nd:YAG pulsed laser. The effects of process parameters on starting notch (SN) dimension and morphology were investigated by both finite element method (FEM) simulations and physical experiments for various process parameters. Optical microscopy and the scanning electron microscope (SEM) were used for the measurement of SN dimension and the observation of SN morphology in the experiment. The results were compared with the predictions. It was found that the FEM simulations results showed good consistency with the experiments, which indicates that the finite element model is feasible and reliable. Based on the principal findings from the two methods, optimum ranges of process parameters for different fracture splitting connecting rods were predicted, which are a flexibly adjusting notch depth, a curvature radius less than 0.08 mm and an opening angle within the range 18–26°. The results indicate that the predicting ranges are suitable for making good SNs, which has also been proved by the fracture splitting experiments.