3D打印熔丝温度对PLA断面形貌和力学性能的影响

Effect of 3D Printing Fusing Temperature on Fracture Surface Morphology and Mechanical Properties of PLA

为提高3D打印制件的力学性能,采用扫描电镜(SEM)和WDW电子万能试验机等研究了3D打印熔丝温度对聚乳酸(PLA)材料断面微观形貌和力学性能的影响规律。结果表明,较高的熔丝温度不仅影响PLA断面纤维形貌,还可以提高聚乳酸熔体质量流动速率、制件的拉伸强度和压缩强度。当熔丝温度为215℃时,材料熔体质量流动速率为16.2 g/10min, PLA断口整体表观质量均匀,单丝排列紧密且均匀分布,打印铺层路径平整,孔隙率仅占比11.4%。PLA材料拉伸强度和压缩强度均随熔丝温度的增加呈现先升高后降低的趋势,拉伸强度提升主要得益于材料有效抗拉横截面积的增加,而压缩强度提升得益于相邻线材及铺层界面黏结性能的改善。当熔丝温度为215℃时,PLA制件拉伸强度和压缩强度分别达到36.9、61.3 MPa。

In order to improve the mechanical properties of three dimensional(3 D)printing parts, the effect of 3 D printing fusing temperature on the fracture surface morphology and mechanical properties of polylactic acid(PLA)material was studied.The results show that higher fusing temperature not only affects the fracture surface fiber morphology of PLA,but also improves the melt flow rate, tensile strength and compressive strength of PLA.When the fusing temperature is 215 ℃,the melt flow rate is 16.2 g/10 min, the overall apparent quality of the PLA fracture is uniform, and the monofilaments are tightly arranged and evenly distributed.The 3 D printed ply path is smooth, and the porosity of PLA only accounts for 11.4%.As the fusing temperature increases, the tensile strength and compressive strength of the PLA both increase first and then decrease.The improvement of tensile strength is mainly due to the increase of effective tensile cross-sectional area of PLA,and the increase of compressive strength benefits from the improvement of the bonding properties of adjacent wires and ply interfaces.And when the fusing temperature is 215 ℃,the tensile strength and compressive strength of PLA parts reach 36.9 MPa and 61.3 MPa, respectively.