Buj-Corral Irene, Domínguez-Fernández Alejandro, Durán-Llucià Ramón
School of Engineering of Barcelona (ETSEIB), Department of Mechanical Engineering, Universitat Politècnica de Catalunya (UPC), Avinguda Diagonal, 647, 08028 Barcelona, Spain.
Materials (Basel). 2019 Nov 21;12(23):3834. doi: 10.3390/ma12233834.
In the present paper, we address the influence of print orientation angle on surface roughness obtained in lateral walls in fused deposition modelling (FDM) processes. A geometrical model is defined that considers the shape of the filaments after deposition, in order to define a theoretical roughness profile, for a certain print orientation angle. Different angles were considered between 5° and 85°. Simulated arithmetical mean height of the roughness profile, Ra values, were calculated from the simulated profiles. The Ra simulated results were compared to the experimental results, which were carried out with cylindrical PLA (polylactic acid) samples. The simulated Ra values were similar to the experimental values, except for high angles above 80°, where experimental roughness decreased while simulated roughness was still high. Low print orientation angles show regular profiles with rounded peaks and sharp values. At a print orientation angle of 85°, the shape of the profile changes with respect to lower angles, showing a gap between adjacent peaks. At 90°, both simulated and experimental roughness values would be close to zero, because the measurement direction is parallel to the layer orientation. Other roughness parameters were also measured: maximum height of profile, Rz, kurtosis, Rku, skewness, Rsk, and mean width of the profile elements, Rsm. At high print orientation angles, Rz decreases, Rku shifts to positive, Rsk slightly increases, and Rsk decreases, showing the change in the shape of the roughness profiles.
在本文中，我们探讨了打印方向角对熔融沉积成型（FDM）工艺中侧壁表面粗糙度的影响。定义了一个几何模型，该模型考虑了沉积后细丝的形状，以便为特定的打印方向角定义理论粗糙度轮廓。考虑了5°至85°之间的不同角度。从模拟轮廓计算粗糙度轮廓的模拟算术平均高度Ra值。将Ra模拟结果与使用圆柱形聚乳酸（PLA）样品进行的实验结果进行比较。模拟的Ra值与实验值相似，但在80°以上的高角度除外，在该角度下实验粗糙度降低而模拟粗糙度仍然很高。低打印方向角显示出具有圆形峰值和尖锐值的规则轮廓。在打印方向角为85°时，轮廓形状相对于较低角度发生变化，相邻峰值之间出现间隙。在90°时，模拟和实验粗糙度值都将接近零，因为测量方向与层方向平行。还测量了其他粗糙度参数：轮廓最大高度Rz、峰度Rku、偏度Rsk和轮廓元素平均宽度Rsm。在高打印方向角下，Rz减小，Rku变为正值，Rsk略有增加，Rsm减小，表明粗糙度轮廓形状发生了变化。
