Relating print velocity and extrusion characteristics of 3D-printable cementitious binders: Implications towards testing methods
Relating print velocity and extrusion characteristics of 3D-printable cementitious binders: Implications towards testing methods
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DOI：
10.1016/j.addma.2021.102127
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发表时间：
2021-10
影响因子：
11
通讯作者：
Sooraj A.O. Nair;S. Panda;Avinaya Tripathi;N. Neithalath
中科院分区：
文献类型：
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作者：
Sooraj A.O. Nair;S. Panda;Avinaya Tripathi;N. Neithalath
本研究旨在将打印速度与从受控滑块挤压测试中提取的关键参数联系起来，以建立一种测试方法，以加快胶凝材料3d打印材料和工艺参数的选择。更高的打印速度，虽然有助于更快的施工，结果需要更高的挤出压力，而较低的速度通过影响，如水过滤干扰挤出质量。稳态压力和死区长度对应于所选的筒模几何形状和打印速度从挤出力-滑枕位移关系中提取。稳态压力随打印速度的增加而增加，死区长度随打印速度的增加而减小。喷嘴出口和打印床之间的沉积压力随着打印速度的增加而增加，并与挤出压力成正比。这些结果用于确定所选几何形状和打印机系统的理想打印速度范围，从而同时优化挤出压力和死区长度。当材料微观结构参数（颗粒体积分数与平均尺寸的平方之比）越高时，打印速度范围、稳态压力和死区长度的下限越低，说明合理的材料设计对于保证胶凝粘合剂的高效3D打印的重要性。
This study aims to relate print velocity to critical parameters extracted from a controlled ram extrusion test, towards a test method to expedite the selection of materials and process parameters for 3D-printing of cementitious materials. Higher print velocities, while aiding faster construction, results in a need for higher extrusion pressure, while lower velocities interfere with extrudate quality through effects such as water filtration. Steady-state pressures and dead-zone lengths corresponding to a chosen barrel-die geometry and print velocity are extracted from extrusion force-ram displacement relationships. The steady state pressure increases with print velocity, while the dead-zone length decreases. The deposition pressure between the nozzle exit and the print bed increases with increase in print velocity, and is proportional to the extrusion pressure. These results are used to define a range of desirable print velocities for the chosen geometry and the printer system, so that the extrusion pressure and dead-zone lengths are simultaneously optimized. The lower limit of the print velocity range, steady-state pressure, and dead-zone lengths are all lower when the material microstructural parameter (ratio of particle volume fraction to square of mean size) is higher, indicating the importance of appropriate material design in ensuring efficient 3D printing of cementitious binders.