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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.

浆料浸渍法制备氢磷灰石/钛仿生材料具有良好的成形性和组织控制能力。这两种成分的梯度层是根据高温处理过程中发生的热应力降低和最佳生物相容性的最佳组成剖面形成的。这种梯度层是通过浆液浸渍成功地形成的。从分散介质、分散剂、粘结剂、生粉等方面对浆料的分散性、沉降性、粘度、流变性和屈服值进行了详细的研究。研究了低粘度和高粘度浆料，以扩大膜厚控制的可能性。对于低粘度的浆体，需要抑制分散颗粒的沉降，而对于高粘度的浆体，了解浆体的流动特性对于确定屈服值是重要的，这是精确控制浸涂层厚度所必需的。高粘度浆料无沉淀，膜厚随粘度和屈服值的变化比较容易控制。浸渍涂层的固结过程，包括干燥和脱脂，遵循传统的粉末冶金技术，特别关注与成分分级有关的烧结收缩问题。在本研究中，优化了工艺条件，以获得良好的生物相容性梯度层。然而，通常情况下，最佳工艺条件取决于被加工对象的材料种类、形状和大小，在将现有工艺条件应用于实际齿根生产时，需要进行修改，并进行或多或少的实用和技术研究。