Liu Jiangwei, Zhao Kangkang, Wang Xiebin, Li Hu
School of Energy and Power Engineering, Shandong University, Jinan 250061, China.
Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061, China.
Materials (Basel). 2024 Oct 11;17(20):4968. doi: 10.3390/ma17204968.
The topological characteristics of the down-skin surfaces for as-built components by laser powder bed fusion (LPBF) are particularly representative, while the study on the improvement of the surface quality of these surfaces remains largely unexplored. Herein, the laser polishing of LPBF-built components with different inclination angles was systematically investigated with an emphasis on the down-skin surfaces. Our result shows that the topography of the top surface is independent of the inclination angle, and the surface topography of the down-skin surface is dominated by additional angle-dependent surface characteristics. It also indicates that the surface roughness can be reduced sharply when increasing the laser power from 40 W to 60 W, and the reduction slows down when further increasing the laser power while decreasing the scanning speed leads to a progressive improvement of the surface morphology. Moreover, a second-order regression model was established to evaluate the influence of the initial surface morphology and polishing parameters on the polished surface roughness and to achieve surface roughness optimization. Therefore, our established methodology can be readily applied to surface morphology manipulation and process optimization for laser polishing of widely used metals and alloys fabricated by the additive manufacturing process.
激光粉末床熔融（LPBF）制造的部件的下表面拓扑特征具有特别的代表性，然而对于改善这些表面的表面质量的研究在很大程度上仍未得到充分探索。在此，系统地研究了不同倾斜角度的LPBF制造部件的激光抛光，重点关注下表面。我们的结果表明，上表面的形貌与倾斜角度无关，而下表面的表面形貌则由额外的角度相关表面特征主导。这也表明，当激光功率从40W增加到60W时，表面粗糙度可大幅降低，而进一步增加激光功率时降低速度减缓，同时降低扫描速度会使表面形貌逐步改善。此外，建立了二阶回归模型，以评估初始表面形貌和抛光参数对抛光表面粗糙度的影响，并实现表面粗糙度优化。因此，我们建立的方法可轻松应用于通过增材制造工艺制造的广泛使用的金属和合金的激光抛光的表面形貌操纵和工艺优化。
