A study of compaction characteristics and properties after sintering of ceramic powders

陶瓷粉末烧结后的压实特性及性能研究

• 批准号: 61550056
• 负责人: SHIMA Susumu
• 金额: $ 1.15万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1986
• 资助国家: 日本
• 起止时间: 1986 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61550056/
• 关键词: ceramic powder; Characteristics of powder; constitutive equation; three-dimensional compaction; compaction criterion; isostatic compaction; 剛塑性有限要素法; 窒化けい素紛末; 粉末成形; 焼結助剤; 三次元圧縮

The main objective of this study is to carry out three-dimensinal compaction of ceramic powders to investigate their characteristics and thereby to develop constitutive equations or compaction criteria for general stress state. If this could be done, the properties after sintering could be investigated in terms of the compaction criteria.The three-dimensional compaction was carried out using a ceramic powder (Si3N4), either with or without sintering additives and the characteristics in compaction were discussed. In a low stress range the ceramic powders are said to behave in particular manner, i.e. tapping of the powder particles, fracture of the agglomerates and rearranging of the particles are likely to occur. The following results were obtained.(1) The powder with sintering additives can be compacted in a lower stress level compared to that without additives.(2) The compaction criterion apperars to be given by part of ellipsoid in the principal stress space.(3) The values of the parameters which are included in the criterion are quite dependent on the characteristics of the powders. The relationship between the parameters and the characteristics should be further investigated.By employing the characteristics and the constitutive equations for the powders, the rigid-plastic finite element analysis of isostatic compaction (CIP) was carried out. The shape of the compacts and distribution of the density in the compacts depended on the characteristics of the powder and also on the strength of the capsule. The compacts after sintering will thus provide different properties depending on the characteristics. This is a very important point in compactin of ceramic powders.

本研究的主要目的是对陶瓷粉末进行三维压实，研究其特性，从而制定一般应力状态的本构方程或压实标准。如果可以做到这一点，就可以根据压制标准研究烧结后的性能。使用陶瓷粉末（Si3N4）进行三维压制，无论有或没有烧结添加剂，并讨论了压制特性。在低应力范围内，陶瓷粉末据称会表现出特定的行为，即可能发生粉末颗粒的敲击、团聚体的破裂和颗粒的重新排列。得到了以下结果：(1)与不含添加剂的粉末相比，添加烧结添加剂的粉末可以在较低的应力水平下进行压实。(2)压实准则似乎是由主应力空间中的部分椭球体给出的。(3)准则中包含的参数值很大程度上取决于粉末的特性。参数与特性之间的关系有待进一步研究。利用粉体的特性和本构方程，进行等静压成形(CIP)的硬塑性有限元分析。压块的形状和压块中的密度分布取决于粉末的特性以及胶囊的强度。因此，烧结后的压坯将根据特性提供不同的性能。这是陶瓷粉末压实中非常重要的一点。

项目成果

Shima, Susumu and Nakanishi, Toshisuke: "Compaction characteristics of Si_3N_4 Powder and its Application to Analysis Isostatic Compaction" Journal of the Society of Material Science, Japan. 37. 70-76 (1988)

Shima、Susumu 和 Nakanishi、Toshisuke：“Si_3N_4 粉末的压实特性及其在等静压分析分析中的应用”，日本材料科学学会杂志。

島進,中西利介: 材料. 37. 70-76 (1988)

Susumu Shima，Risuke Nakanishi：材料。 37. 70-76 (1988)