权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Crystallographic study on phase transformation and artificial interface in ceramics

陶瓷相变和人工界面的晶体学研究

基本信息

批准号：
09650763
负责人：
NAKAI Kiyomichi
金额：
$ 2.24万
依托单位：
Ehime University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

The phase-decomposition processes and -equilibria in ceramics and intermetallics have been investigated, because their properties depend largely on the microstructures. In the present investigations, the morphology and crystallography of the microstructures have been extensively examined, and the mechanisms for the microstructure evolutions have been clarified.Details in the present investigations are as follows ; the mechanisms of carbide and/or oxide precipitation in mechanically alloyed Mo-HfC or Mo-TiC composite materials in high-temperature regions, the effects of impurities on oxide formation in oxygen-doped silicon, the mechanism of purification of silicon by the oxide-precipitation, the mechanisms of phase-decomposition and -equilibria in TiAl-based intermetallics, the effects of addition of Cr, Zr or Mo to Ti-Al binary alloys on the stability of β phase, the mechanism of the β phase decomposition in the ternary Ti-AI-X alloys, the effects of nitrides and/or carbide nucleation on formation of primary ferrite in low C steels, the effects of addition of various elements on phase-decomposition and -equilibria in high Cr steels, the mechanism of phase-decomposition and -equilibria in Ti-based materials for human being, the aging processes in Al alloys, and the formation processes of various intermetallic compounds.The structures of interphase interfaces have been examined, and clarified to be dominant factor controling size distribution of precipitates and precipitation anisotropy by the crystallographic analyses for phase-equilibria and -decomposition in ceramics and alloys. It is concluded that crystallographic analyses for phase-transformation and -equilibrium are indispensable to control the material properties.

人们对陶瓷和金属间化合物的相分解过程和相平衡进行了研究，因为它们的性能很大程度上取决于微观结构。在目前的研究中，对微观结构的形态和晶体学进行了广泛的研究，并阐明了微观结构演变的机制。目前研究的详细信息如下；高温区机械合金化Mo-HfC或Mo-TiC复合材料中碳化物和/或氧化物沉淀的机理，杂质对氧掺杂硅中氧化物形成的影响，氧化物沉淀提纯硅的机理，TiAl基金属间化合物中相分解和相平衡的机理，Cr、Zr或Mo添加的影响 Ti-Al二元合金对β相稳定性的影响，三元Ti-Al-X合金中β相分解的机理，氮化物和/或碳化物形核对低C钢中初生铁素体形成的影响，各种元素的添加对高Cr钢中相分解和相平衡的影响，钢中相分解和相平衡的机理人类钛基材料、铝合金的时效过程以及各种金属间化合物的形成过程。通过陶瓷和合金中相平衡和分解的晶体学分析，检验了相间界面的结构，并阐明了控制析出物尺寸分布和析出物各向异性的主导因素。结论是相变和相平衡的晶体学分析对于控制材料性能是必不可少的。