FDM成型性能的影响因素分析及试验研究

发布时间：2018-06-06 23:05

本文选题：熔融沉积成型 + 成型方向　；参考：《哈尔滨理工大学》2017年硕士论文

【摘要】：熔融沉积成型(Fused Deposition Modeling,FDM)工艺是快速成型制造技术中应用最为广泛的,但成型件的机械性能与质量仍制约着其在更多方面的应用。本文以理论分析为依据设计工艺试验,对影响熔融沉积成型制件机械性能的因素进行详细分析。论文首先对熔融沉积成型的基本原理、成型特点、成型材料等做出详细说明。然后分析了原理性误差、工艺性误差以及后处理误差的形成机理,并总结其影响规律,提出相应的解决策略,这为提高制件综合性能与优化成型工艺参数提供了理论基础和指导准则。针对熔融沉积成型的填充方式这一工艺参数设计实验,使用PLA(聚乳酸)热塑性丝材,通过分别改变填充密度、层高度以及填充路径构建若干组试验样件。对实验样件进行拉伸实验,整理实验数据,分析实验结果,比较不同填充密度、不同层高度以及不同填充路径下试件的抗拉性能及精度之间的差异。并结合对断口形貌的宏观分析与SEM图像进行分析,判断试件的断裂模式。其中,填充密度在90%时断裂伸长率骤减,较小的层高度会削弱试件的强度,横向填充路径下试件的力学性能较好。最后以熔融沉积成型零件的成型方向与成型角度为研究对象,使用ABS热塑像材料,分别在水平、垂直、竖直各个成型方向中的五个不同成型角度下构建实验样件。通过拉伸实验、弯曲实验与对断口的显微图像观测相结合的方法,分别对试件的抗拉极限强度、弹性模量、抗弯强度进行分析与比较,并分别测量各个试件的表面粗糙度值与尺寸,比较不同成型方向与成型角度下表面精度与尺寸精度差异,并结合对成型时间与成型材料的使用量的测量结果确定最佳成型方向与成型角度。其中,ZY方向下的成型件其断裂伸长率明显低于在YX、YZ方向下的成型件;YZ方向下试件的尺寸相对误差最小;试件H-0和V-0,具有较高的抗拉强度与弹性模量与抗弯强度,机械性能最好。
[Abstract]:The fused Deposition Modeling (FDM) process is the most widely used in rapid prototyping technology, but the mechanical properties and quality of the molded parts still restrict its application in many fields. Based on the theoretical analysis, the factors influencing the mechanical properties of the fused deposition forming parts are analyzed in detail. Firstly, the basic principle, characteristics and materials of melt deposition molding are described in detail. Then, the forming mechanism of the principle error, the technological error and the post-processing error is analyzed, and the influence law is summarized, and the corresponding solving strategy is put forward. This provides a theoretical basis and guidance for improving the comprehensive properties of the parts and optimizing the molding process parameters. In view of the design experiment of the filling mode of melt deposition, a number of test samples were constructed by changing the filling density, layer height and filling path by using PLA (Poly (lactic acid) thermoplastic filament. The tensile test was carried out, the experimental data were arranged, the experimental results were analyzed, and the difference of tensile properties and precision of the specimens with different filling density, different layer height and different filling paths was compared. The fracture mode of the specimen is judged by the macroscopic analysis of fracture surface and the analysis of SEM image. When the filling density is 90, the elongation at break decreases sharply, and the strength of the specimen is weakened by the lower layer height. The mechanical properties of the specimen are better under the transverse filling path. Finally, taking the forming direction and angle of melt deposition forming part as the research object, using ABS thermoplastic materials, the experimental samples are constructed at five different forming angles in horizontal, vertical and vertical molding directions respectively. The tensile ultimate strength, elastic modulus and flexural strength of the specimen were analyzed and compared by tensile test, bending test and microscopic image observation. The surface roughness and dimension of each specimen were measured, and the difference of surface precision and dimension precision under different forming direction and angle was compared. The best forming direction and angle are determined according to the measurement results of molding time and material usage. The elongation at break of the molded parts in the direction of ZY is obviously lower than that in the direction of YXY and the relative error of the dimension of the specimens in the direction of YZ is the smallest, and the specimens H-0 and V-0 have higher tensile strength, modulus of elasticity and flexural strength, and the mechanical properties are the best.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH16

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