A carbon efficiency approach for laser welding environmental performance assessment and the process parameters decision-making

As a new generation of manufacturing technology, laser welding is widely applied in the fields of automobile, aerospace, etc. with its compelling advantages of high flexibility, quality, and energy density. However, the environmental performance of the laser welding process is not clear so far. There is a lack of systematic analysis of the laser welding process that takes all the energy sources and material consumption into consideration to reflect the actual environmental impact and evaluate the process parameter for decision-making. In this study, a parameterized model linking the carbon emissions and laser welding parameters is established. Based on this, a carbon efficiency evaluation approach is proposed to reveal the trade-off between carbon emissions and the added manufacturing value for decision-making on the premise of ensuring the welding quality. To verify the effectiveness of this approach, the carbon efficiency of the laser butt joint welding process is analyzed as an illustration. The results show that the parametric carbon emission models offer a feasible evaluation of carbon emissions of the laser welding process, with an accuracy of approximately 93.6%. The carbon emissions of the cooling system are 1.78 times that of laser devices. Thus, it dominates the carbon emissions of the laser welding process rather than laser devices. While ensuring the processing quality, increasing the welding speed is the most key way to improve carbon efficiency. The reason for it is that the carbon emissions of auxiliary facilities, e.g., cooling system can be reduced significantly as the reduced welding time. Furthermore, the standby time used, e.g., clamping and taking-off of workpieces, etc., is another key factor affecting the carbon efficiency. Thus, shortening the standby time can also improve the carbon efficiency of the laser welding process.