Gao Guili, Du Zhimin, Zhang Weikun, Liu Qingyi, Su Yanqing, Ni Yunqiang, Shi Dequan
School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin, China.
Technology Research Institute, Weichai Power Co. Ltd., Weifang, China.
3D Print Addit Manuf. 2023 Apr 1;10(2):289-297. doi: 10.1089/3dp.2021.0088. Epub 2023 Apr 12.
Three-dimensional printing (3DP) is considered to be one of the important technologies for a new manufacturing mode. When ceramsite sand is used as a 3DP material to produce a mold (core), the printed layer is prone to deviation from the original location. In this study, the continuous stacking of the printed part deviation was termed as pushing dislocation, and a physical model was designed to investigate the pushing dislocation mechanism. When the gravity of the printing layer and the pressure of the sand scraper decreased, or when the supporting force increased, the angle of the sand scraper and the maximum friction of the prelaying layer on the printed part will reduce the pushing dislocation. To optimize the quality of the ceramsite sand mold, experiments on the pushing dislocation were conducted by altering the recoater speed, layer thickness, and bottom support condition (with or without bottom supporting plate). The sample dimensions were obtained by a 3D imaging scanner, and the gas evolution and ignition loss were measured. The results revealed that the dimensional difference of samples continuously decreased and the pushing dislocation was gradually reduced as the recoater speed and layer thickness increased. The pushing dislocation of the X-direction sample was more severe compared with that of the Y-direction sample. Increasing the layer thickness is an effective way of reducing the pushing dislocation. The bottom supporting plate can reduce the pushing dislocation, but the effect was insignificant.
三维打印（3DP）被认为是新型制造模式的重要技术之一。当陶粒砂用作三维打印材料来制造模具（型芯）时，打印层容易偏离原始位置。在本研究中，将打印部件偏差的连续堆积称为推位错，并设计了一个物理模型来研究推位错机制。当打印层的重力和刮板压力减小，或者支撑力增大时，刮板角度和预铺层对打印部件的最大摩擦力会减小推位错。为了优化陶粒砂模具的质量，通过改变刮板速度、层厚和底部支撑条件（有无底部支撑板）进行了推位错实验。通过三维成像扫描仪获取样品尺寸，并测量气体逸出量和烧失量。结果表明，随着刮板速度和层厚的增加，样品的尺寸差异不断减小，推位错逐渐减少。与Y方向样品相比，X方向样品的推位错更严重。增加层厚是减少推位错的有效方法。底部支撑板可以减少推位错，但效果不显著。
