3D打印速度对PLA制件表面质量和力学性能的影响

Effect of 3D Printing Speed on the Surface Quality and Mechanical Properties of PLA Parts

为了提高熔融沉积型3D打印制件的力学性能,基于单因素控制变量法,利用白光干涉形貌仪、扫描电子显微镜和电子万能试验机等设备,研究了3D打印速度对聚乳酸(PLA)表面质量和力学性能的影响规律。结果表明:较低的外壳速度可改善3D打印制件表面质量,而较高填充速度可提高打印制件力学性能。当外壳速度为40mm/s时,PLA制件表面平整光滑,丝材排列紧密且分布均匀,粗糙度为10.2μm;同时打印过程稳定,出丝顺畅,制件尺寸偏差较小,尺寸精度达到了0.16mm。制件压缩强度差异化与制件截面孔隙率及铺层间粘结面积有关,而拉伸强度和断裂伸长率提升得益于制件残余内应力的降低和丝材及铺层间界面强度的改善,且当填充速度为110mm/s时,制件压缩强度和拉伸强度分别达到了75.7MPa和44MPa,断裂伸长率为2.66%。

In order to improve the mechanical properties of fused deposition modeling 3D printing parts,based on single factor control variable method,the effect of 3D printing speed on the surface quality and mechanical properties of polylactic acid(PLA)parts was studied by using white light interference topography instrument,scanning electron microscope and electronic universal testing machine and other equipment.The results show that lower shell speed can improve the surface quality of 3D printing parts,and higher filling speed can improve the mechanical properties.When the shell speed is 40 mm/s,the surface of PLA parts is flat and smooth and the wires are closely arranged and evenly distributed,and the roughness is 10.2μm.At the same time,not only the printing process is stable and the output of filament is smooth,but also the dimensional deviation of parts is small,and the dimensional accuracy reache 0.16 mm.The difference of compressive strength is related to the porosity of PLA parts and the bonding area between layers.The improvement of tensile strength and elongation at break is due to the reduction of residual internal stress and the improvement of interface strength between filaments and layups.When the filling speed is 110 mm/s,the compressive strength and tensile strength of 3D parts reach 75.7 MPa and 44 MPa respectively,and its elongation at break is 2.66%.