3D打印砂型芯用水基涂料流变性能的研究

Research on Rheological Properties of Water-Based Coating for 3D Printing Sand Core

通过选用不同悬浮剂进行复配,研究了其流变特性对3D打印砂型芯用水基涂料悬浮率、流变性能、涂覆效果等的影响。通过对比试验,确定了在采用流涂的涂覆方式下,3D打印砂型芯用水基涂料的推荐配方。试验结果表明:在钠基膨润土中加入凹凸棒土或海泡石,3D打印砂型芯用水基涂料的屈服值、触变率及湿涂层厚度均有提高,改善涂层的表面光滑度。其中,海泡石的加入对3D打印砂型芯用水基涂料的屈服值、触变率及湿涂层厚度的影响更明显。针对本文中的耐火骨料组合,3D打印砂型芯用水基流涂涂料的屈服值范围应在2690~2 790 mPa·s,触变率范围在5.5%~6.5%。在选择合适的悬浮剂组合条件下,无需加入流变助剂即可使涂料获得满足使用要求的流变效果。

The paper researched the effects of rheological properties on suspension rate, rheological properties and flowing effect of the water-based coating for 3D printing sand core with different suspension agents.Through experiments, the recommended formulas of the water-based coating for 3D printing sand core were determined under the coating method of flowing. The results showed that, by adding attapulgite or sepiolite into sodium bentonite, the yield value, thixotropy rate and wet coating thickness of the water-based coating for the 3D printing sand core were improved. And the surface smoothness of the coating was improved.The addition of the sepiolite had a more obvious effect on the yield value, thixotropy rate and wet coating thickness. For refractory aggregate combinations in this paper, the yield value range of the water-based flow coating for the 3D printing sand core should be in 2 690-2 790 mPa·s, the thixotropic rate ranges from 5.5%to 6.5%. Under the condition of selecting the appropriate combination of suspending agents, the rheological effect of the coating could meet the requirements without adding the rheological additive.