Centrifugal Compaction of Submicron High Purity Alumina Powder
Centrifugal Compaction of Submicron High Purity Alumina Powder
复制标题
亚微米高纯氧化铝粉的离心压实
DOI：
--
复制
发表时间：
1992
期刊：
影响因子：
--
通讯作者：
H. Kuroki
中科院分区：
文献类型：
--
作者：
S. Tashima;M. Sumita;H. Kuroki
研制了一种对陶瓷粉末在模具内施加10 ~ 20kg离心力的离心压实工艺。采用球磨机将亚微米（0.22μm）的高纯氧化铝粉末分散在质量分数为22-28mass %的离子交换水中。滑移的黏度系数为80-2000mP⋅sec。压实过程如下：1)在离心力作用下，氧化铝颗粒在模腔底部沉积，在模腔顶部留下上部清水；2)停止离心机器，清除上部清水；3)将模具底部更换为多孔底部，使沉积物中的水分减少约2质量%，再次对沉积物施加10-20kG的离心力；4)脱水后拆下底部，将压块从模具上剥离。这个过程有以下优点：1)滑块的制备和调节容易，因为滑块的浓度和粘度的影响很小。2)既不需要真空除气过程，也不需要除气剂。3)可在短时间内获得相对绿密度水平在60%以上的压实体。4)石膏模具没有污染。5)可缩短干燥、烧结压块的时间。
A centrifugal compaction process applying a 10-20kG centrifugal force to a slip of ceramic powder in a die has been developed. The slip was prepared by dispersing a submicron(0.22μm) high purity alumina powder in 22-28mass % of ion-exchanged water with a ball mill. The coefficient of viscosity of the slip is 80-2000mP⋅sec.The compaction process is as follows: 1) when the centrifugal force acts, the alumina particles are sedimented in the bottom part of the die cavity, leaving upper clear water in the top part of the cavity; 2) the centrifugal machine is stopped, and the upper clear water is removed; 3) the bottom of the die is replaced by a porous bottom so as to reduce the moisture in the sediment by about 2 mass % with a 10-20kG centrifugal force applied again to the sediment; 4) after dehydration, the bottom is removed and the compact is stripped from the die.This process has the following merits;1) preparing and regulating the slip is easy, because the influence of the slip's concentration and viscosity is small.2) neither a vacuum unaerating process nor unaerating agents are necessary.3) compacts with a relative green density level above 60% can be obtained in a short time.4) there is no contamination from the plaster mold.5) the time for drying and sintering compacts can be shortened.