Optimization of surface roughness and dimensional accuracy in LPBF additive manufacturing

Laser powder bed fusion (LPBF) is one of the most promising additive manufacturing technologies. It has been utilized in the high level and stringent requirements fields such as aerospace and biomedicine industries. However, compared to subtractive manufacturing, the relatively poor surface finish and dimensional accuracy of the LPBF part hamper its widespread applications. In this work, a data-driven framework is proposed to obtain optimal process parameters of LPBF to get satisfactory surface roughness and dimensional accuracy. The effects of key process parameters on the surface roughness and dimensional accuracy are analyzed. Specifically, a machine learning technique is defined to reflect the dimensional accuracy and the surface roughness of the asbuilt products under different combinations of process parameters. Considering the limited experimental data, a machine learning model is introduced to predict the surface roughness and dimensional accuracy in the whole process parameters space. Then the predicted value is considered as an objective value when using the whale optimization algorithm (WOA) to search the global optimal process parameters. In the verification experiments, LPBF parts with better surface finish and dimensional accuracy were obtained with optimized process parameters which indicates that the optimized results are consistent with the experimental results.

Automated summary

The study introduced a data-driven framework to obtain optimal process parameters for laser powder bed fusion (LPBF) in order to achieve satisfactory surface roughness and dimensional accuracy. Machine learning techniques were used to predict the accuracy and surface roughness of LPBF products under different process parameters combinations, leading to the use of a whale optimization algorithm to search for the global optimal process parameters. The experiments verified that LPBF parts with better surface finish and dimensional accuracy could be obtained with the optimized process parameters.