Powder Metallurgical Fabrication of Artificial Tooth Root of Hydroxyapatite/Ti with Bio-mimetic Structure

粉末冶金仿生结构羟基磷灰石/钛人工牙根的制备

基本信息

批准号：
10555239
负责人：
WATANABE Ryuzo
金额：
$ 6.66万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

Slurry dipping method was employed for the processing of hydroxiapatite/Ti biomimetic materials because of its capability of shape forming and microstructural control. The graded layers of both constituents were formed according to an optimum composition profile for the thermal stress reduction which will occur during high temperature processing, and for the optimum bio compatibility. Such graded layers were successfully formed by slurry dipping. Dispersion, sedimentation, viscosity, rheology, as well as yield value, of the slurries were investigated in detail in connection with properties of dispersion medium, dispersion reagent, binder and raw powders. Low- and high-viscosity slurries were investigated to enlarge a possibility of film thickness control. For the low-viscosity slurry it is necessary to suppress the sedimentation of dispersion particles, while for the high-viscosity slurry it turned out to be important to clarify the flow characteristics of the slurry for the determination of the yield value, which is needed for the precise control of the dip-coated layer thickness. The high-viscosity slurry was free from sedimentation, and the control of the film thickness with viscosity and yield value was rather easier. The consolidation process of the dip-coated layer, including drying and debinding, followed conventional powder metallurgical techniques, with particular attention on an issue pertaining to the sintering shrinkage which is characteristic to composition grading. In the present investigation the process conditions were optimized to get a sound graded layer for a better bio-compatibility. In general, however, the optimum process condition depends on material species, shape and size of the objects to be processed, and in applying the present process conditions to actual tooth root production a modification will be necessary with more or less practical and technical study.

由于其形状形成和微结构控制能力，因此采用了浆液浸入方法来处理羟基磷灰石/Ti仿生材料。根据在高温加工期间将发生的热应力减少和最佳生物兼容性的最佳组成曲线形成两种成分的分级层。这种分级层成功地通过浆液浸入形成。详细研究了与分散培养基，分散试剂，粘合剂和原始粉末的性质有关的分散，沉积，粘度，流变学和产量值。研究了低粘度和高粘度浆液，以扩大膜厚度控制的可能性。对于低粘性浆液，有必要抑制分散颗粒的沉积，而对于高粘度浆，事实证明，阐明浆液的流动特性以确定产量值，这一点很重要，这是必需的。浸入涂层层厚度的精确控制。高粘度浆液中没有沉积，用粘度和产量值控制膜厚度非常容易。浸入式涂层层的合并过程（包括干燥和脱落）遵循常规粉末冶金技术，特别关注与烧结收缩有关的问题，这是构成分级的特征。在本研究中，对过程条件进行了优化，以获得声音分级层，以获得更好的生物兼容性。但是，通常，最佳过程条件取决于要处理的物体的物质，形状和大小，并且在将当前的过程条件应用于实际牙根生产中时，将需要进行修改，或多或少实用和技术研究。