3D打印工艺中粘结剂渗透建模与仿真

Modeling and Simulation of Binder Droplet Infiltration in 3D Printing Technology

为了提高3D打印工艺的成型精度,实现对粘结剂渗透形态的预测,本文采用工业CT对砂体材料进行扫描,建立砂体材料的球棒模型,并利用数字岩心技术求得材料物性参数.采用半径与材料喉道半径相等的毛细管模型对粘结剂的渗透过程进行数学建模,由实验的方法对液滴的铺展半径进行采集,求得液滴凝聚单元的理论尺寸,同时运用COMSOL多物理场仿真软件对粘结剂液滴渗透过程进行数值模拟.搭建了实验工作平台,通过高速摄影对液滴渗透过程进行采集,并借助电子显微镜观测液滴的凝聚形态,将实验结果与仿真结果进行对比,验证了数值模拟所构建的粘结剂渗透模型的有效性.本文不但对渗透实验具有一定的指导意义,也为工艺参数优化提供了理论依据.

To improve the forming precision and predict the nucleus size of binder droplet infiltration in 3D printing technology, the industrial CT was used to scan the sand material, so as to establish ball-and- stick model of the material in this paper. The physical property parameters of materials were calculated by digital core technology. A capillary model was established for the mathematieal model of the binder drop- let infiltration process, whose radius is equal to the radius of the throat of the material. The spreading ra- dius of binder droplet on the material was obtained by using the experimental method, then the size of the agglomeration unit body was calculated by theoretical equation. The process of binder droplet infiltration was simulated by the software of COMSOL. The experimental platform was constructed, in which the process of infiltration was recorded by high speed digital video camera. The nucleus size of the agglomera- tion unit was observed by electron microscope. The effectiveness of the model of the binder droplet infil- tration in numerieal simulation is verified by eomparing experimental results and simulation results. The research is important to infiltration experiments, providing a theoretical basis for the optimization of pa- rameters in practical processing.