3D打印零件的尺寸精度及控制

Dimensional accuracy and control of 3D printed parts

在大型零件的成形过程中,零件底部翘曲变形导致精度丧失是熔融沉积增材制造技术的一个突出问题。以熔融沉积成型(FDM)3D打印制件的底部翘曲变形为研究对象,建立了一种FDM翘曲变形的数学模型,通过标准正交试验设计研究喷嘴温度、分层厚度、托板温度、填充密度和堆积层数及断面长度对FDM 3D打印翘曲变形的影响,应用极差分析和方差分析得到了最优的工艺参数组合。研究结果表明,分层高度为0.2 mm,喷嘴温度为210℃,托板温度为55℃,填充率为40%,底层堆积层数为25层,断面长度为20 mm,此时翘曲变形量最小,为0.402 mm。对翘曲变形影响程度主次顺序为:分层厚度>堆积层数>喷嘴温度>断面长度>填充密度>托板温度。随着堆积层数的增加和断面长度的减小,翘曲变形量呈减小趋势。

In the forming process of large‑sized parts,the precision loss caused by the warping deformation at the bottom of the part is a prominent problem in the melt deposition additive manufacturing technology.Taking the bottom warping deformation of melt deposition molding(FDM)3D printed parts as a research object,an orthogonal experiment was designed to study the effects of nozzle temperature,layer thickness,bracket temperature,filling density,the number of layers,and section length on the warping deformation of FDM 3D printing.The optimal combination of process parameters was obtained through range analysis and variance analysis.The results indicated that the warpage deformation obtained a minimum value of 0.402 mm at a layer height of 0.2 mm,a nozzle temperature of 210℃,a bracket temperature of 55℃,a filling rate of 40%,a number of bottom layers of 25,and a section length of 20 mm.The factors of influence on the warpage deformation was by a order of layer thickness>number of layers>nozzle temperature>section length>filling density>bracket temperature.The warping deformation decreased with an increase in the number of layers but a decrease in the section length.