Evaluation of powder loading and flow properties of Al2O3 ceramic injection molding feedstocks treated with stearic acid
Evaluation of powder loading and flow properties of Al2O3 ceramic injection molding feedstocks treated with stearic acid
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DOI：
10.1016/j.ceramint.2019.06.273
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发表时间：
2019-11-01
影响因子：
5.2
通讯作者：
Filip, Petr
中科院分区：
文献类型：
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作者：
Hnatkova, Eva;Hausnerova, Berenika;Filip, Petr
陶瓷通过注射成型的可加工性在于达到足够高的固体负载，尽管Al2O3陶瓷颗粒具有相应高的比表面积的亚微米尺寸。高（临界）固体含量限制了由化合物的流动性质反映的注射成型。本文的重点是临界固体负荷（CSL）参数的评估以及流动特性的可靠描述。由于表面活性剂通常掺入聚合物粘合剂中，因此最常用的硬脂酸（SA）与三种不同的粘合剂组合以实现更高的CSL。CSL由基于从50体积%到60体积%连续增加粉末负载的混合扭矩的演变来确定。用毛细管流变仪分析了具有固定粉末负载（52体积%）的Al2O3原料的流动性，并且通过主曲线模型预测粘度数据，所述主曲线模型表示没有可调（拟合）参数的固定功能结构。唯一的变量是剪切速率和表面剂（SA）浓度。与实验数据的偏差不超过实验误差。
Processability of ceramics via injection molding consists in reaching sufficiently high solid loading despite submicrometric size of Al2O3 ceramic particles with a correspondingly high specific surface area. High (critical) solid loading limits injection molding reflected by flow properties of the compounds. This paper is focused on the evaluation of the critical solid loading (CSL) parameter as well as reliable description of the flow properties. As surface active agents are usually incorporated in polymer binders, most often used stearic acid (SA) is combined with three different binders to achieve higher CSL. CSL is determined from evolution of mixing torque based on continuously increasing powder loading from 50 to 60 vol %. Flowability of Al2O3 feedstocks with a fixed powder loading (52 vol %) was analyzed with a capillary rheometer, and viscosity data were predicted by a master curve model representing a fixed functional structure with no adjustable (fitting) parameters. The only variables are shear rate and surface agent (SA) concentration. A deviation from the experimental data does not exceed an experimental error.