Valiyakath Vadakkan Habeeb Nismath, Islam Rabiul, Chou Kevin
Department of Industrial Engineering, University of Louisville, Louisville, KY 40292, USA.
Materials (Basel). 2024 May 30;17(11):2639. doi: 10.3390/ma17112639.
Among various metal additive manufacturing (AM) technologies, L-PBF is known for fabricating intricate components. However, due to step edges and powder particle attachments, attaining a good surface finish is challenging, especially on downskin surfaces. Contour scanning has potential to improve surface quality because such scanning may dominate the surface formation of sloped features. This study evaluates the effects of pre- and post-contouring strategies on the sloped downskin surfaces fabricated using a commercial L-PBF system with Ti6Al4V powder. L-PBF parts printed at inclination angles 30°, 45° and 60° were investigated. A double-contouring approach with varying processing conditions was employed and surface characteristics were analyzed using data acquired by white light interferometry. The average surface roughness, S, surface skewness, S, and percentage area of powder particles attached onto surfaces were statistically evaluated. The lowest S obtained for pre- and post-contoured samples is 14.08 µm and 18.88 µm, respectively. For both strategies, the combination of a low laser power and a high scan speed on the interface of downskin surface and underneath powder results in smoother surfaces. However, while comparing both strategies, pre-contouring gives better surface finish for samples built at similar processing conditions, with a difference of nearly 5 µm in S.
在各种金属增材制造（AM）技术中，激光粉末床熔融（L-PBF）以制造复杂部件而闻名。然而，由于台阶边缘和粉末颗粒附着，获得良好的表面光洁度具有挑战性，尤其是在向下表面上。轮廓扫描有潜力改善表面质量，因为这种扫描可能主导倾斜特征的表面形成。本研究评估了轮廓扫描前后策略对使用商用L-PBF系统和Ti6Al4V粉末制造的倾斜向下表面的影响。研究了以30°、45°和60°倾斜角打印的L-PBF零件。采用了具有不同加工条件的双重轮廓方法，并使用通过白光干涉测量获得的数据分析了表面特征。对平均表面粗糙度S、表面偏度S以及附着在表面上的粉末颗粒的面积百分比进行了统计评估。轮廓扫描前后样品获得的最低S分别为14.08 µm和18.88 µm。对于这两种策略，在向下表面与下方粉末的界面上采用低激光功率和高扫描速度的组合可产生更光滑的表面。然而，在比较这两种策略时，在相似加工条件下制造的样品，轮廓扫描前的表面光洁度更好，S相差近5 µm。
