熔融沉积成型3D打印利用逐层累积的方法可以快速制造出复杂型腔的零件和模型，但此制造方式下零件容易出现表面缺陷和尺寸误差。文章针对零件在打印过程中悬垂部分底面出现的筋状拉丝问题，通过前处理添加致密层和后处理利用化学溶液抛光的方法进行实验，测量打印零件悬垂部分圆柱度，以直接打印零件测量的圆柱度为基准。结果表明：只经过前处理的零件其圆柱度相比未做处理的零件提升了13.6%。只经过后处理的零件其圆柱度相比未做处理的零件提升了18.7%。前处理与后处理相结合而得到的零件其悬垂部分圆柱度精度提升了64.3%。研究验证了前处理与后处理结合可有效地解决悬垂部分出现的筋状拉丝情况。

Fused deposition modeling 3D printing can quickly manufacture parts and models with complex cavities using the layer-by-layer accumulation method, but the parts are prone to surface defects and dimensional errors in this manufacturing method. In order to solve the problem of rib drawing on the bottom surface of the overhang part during the printing process of the part, the cylindricity of the overhang part of the printed part was measured by adding a dense layer in the pre-treatment and the method of chemical solution polishing in the post-treatment, and the cylindricity measured by the direct printing part was taken as the benchmark. The results show that the cylindricity of the parts that have only been pre-treated is increased by 13.6% compared with the parts that have not been treated. The cylindricity of the post-treated parts was increased by 18.7% compared to the untreated parts. The cylindricity accuracy of the overhang part of the part obtained by combining pre-treatment and post-treatment is increased by 64.3%. The study verified that the combination of pre-treatment and post-treatment can effectively solve the tendon-like wire drawing in the overhang.