ABSTRACT

In this study, paste backward extrusion is introduced for fabrication of sodium beta-alumina electrolyte closed-end tubes (with a wall thickness of 1 mm and external diameter of 8.0 mm). For this purpose, the two-piece extrusion die was designed and extrudable water-based paste was prepared by using sodium beta-alumina powder, polyvinyl pyrrolidone, as a binder, and ethylene glycol as a plasticizer. The effect of solvent content on the rheological parameters of the paste and the ram extrusion velocity on the liquid phase separation are investigated. The results indicate that the optimum solvent content for making the extrudable paste is in the range of 30–35 wt-%, and the liquid phase separation is obviously occurred when the ram velocity is lower than 1.2 mm s⁻¹. It was also shown that by using backward extrusion, and by applying optimum conditions, closed-end tubes with high density (about 97%) and good surface quality could be fabricated successfully.

摘要

在这项研究中，引入糊状反向挤压来制造钠 β-氧化铝电解液封闭端管（壁厚为 1 mm，外径为 8.0 mm）。为此，设计了两片式挤出模具，以β-氧化铝粉、聚乙烯吡咯烷酮为粘合剂、乙二醇为增塑剂制备了可挤出水性糊剂。研究了溶剂含量对糊状物流变参数的影响和柱塞挤出速度对液相分离的影响。结果表明，制备可挤出糊剂的最佳溶剂含量在30-35 wt-%范围内，当柱塞速度低于1.2 mm s ^-1时，液相分离明显发生。. 还表明，通过使用反向挤压，并通过应用最佳条件，可以成功制造具有高密度（约 97%）和良好表面质量的封闭端管。