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Strengthening of Nano-lamellar Materials by Controlling of Nano-structure of Lamellar Interface

通过控制层状界面的纳米结构强化纳米层状材料

基本信息

批准号：
17360309
负责人：
MARUYAMA Kouichi
金额：
$ 9.79万
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：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17360309/
关键词：
Intermetallics Titanium Aluminide Nano lamellar Structure Lamellar Boundary Design Strengthening of Materials Hall-Petch Relation High Temperature Creep Microstructural Degradation ミスフィット転位

项目摘要

TiAl alloys are the most promising light materials for high temperature structural applications. The alloys take a lamellar microstructure consisting of α_2Ti_3Al and γTiAl phases, and their strength is affected significantly by the microstructure of lamellar interfaces. It was examined in this study how to control the microstructure of the interfaces.1. Misfit dislocation is absent on α_2/7 lamellar interfaces when a y lamella is thin, and the lamellar alloys are in a coherent state (with high internal stress state). Misfit dislocations are introduced onto lamellar interfaces above a critical γ thickness of γ_c and the alloys change to a semi-coherent state. The misfit dislocation network consists of 1/2<110] ordinary dislocations and 1/6<112] super partial dislocations.2. 1/2<110] dislocations are introduced ahead of the others, because of the larger lattice misfit in <110] directions and the higher mobility of 1/2<110] dislocations. The density of misfit dislocations at a given lamellar thickness increases with increasing amount of lattice misfit.3. Spacing of misfit dislocations decreases with increasing misfit strain, and is finer in Zr added TiAl alloys than in Nb added alloys. The critical γ thickness γ_c for the introduction of misfit dislocations decreases in the Zr added alloys. Therefore, one can control the introduction of misfit dislocations by changing lattice misfit with alloy addition.4. Thermal stability of lamellar interfaces is crucial to high creep strength, and α_2/γ interfaces have the highest stability among several types of interfaces in TiAl lamellar alloys. High heating rate during hear treatment results in a high density of α_2/γ interfaces.

TiAl合金是最有前途的高温结构轻质材料。该合金呈由α_2Ti_3Al和γTiAl相组成的层状组织，其强度受层状界面组织的影响显着。本研究探讨了如何控制界面的微观结构： 1．当 y 片层较薄且片层合金处于共格状态（具有高内应力状态）时，α_2/7 片层界面上不存在失配位错。错配位错被引入到高于临界 γ 厚度 γ_c 的层状界面上，并且合金转变为半共格状态。失配位错网络由1/2<110]普通位错和1/6<112]超部分位错组成。2． 1/2<110]位错先于其他位错引入，因为<110]方向上晶格失配较大，并且1/2<110]位错的迁移率较高。在给定片层厚度下，失配位错的密度随着晶格失配量的增加而增加。3．失配位错的间距随着失配应变的增加而减小，并且在添加 Zr 的 TiAl 合金中比在添加 Nb 的合金中更细。添加Zr的合金中引入失配位错的临界γ厚度γ_c减小。因此，可以通过添加合金改变晶格失配来控制失配位错的引入。4．层状界面的热稳定性对于高蠕变强度至关重要，其中α_2/γ界面是TiAl层状合金中几类界面中稳定性最高的。热治疗期间的高加热速率导致α_2/γ界面的高密度。

项目成果

期刊论文数量（0）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Effects of α_2 Spacing on Creep Deformation Characteristics of Hard Oriented PST Crystals of TiAl Alloy

α_2间距对TiAl合金硬取向PST晶体蠕变变形特性的影响

DOI：
发表时间：
2005
期刊：
Intermetallics 13・10
影响因子：
0
作者：
鳥山康成;Yasunari Toriyama;Yasunari Toriyama;Yasunari Toriyama;鳥山康成;Yasunari Toriyama;Hanliang Zhu;Hanliang Zhu;Hanliang Zhu;Hanliang Zhu;Hanliang Zhu;Hanliang Zhu;Kouichi Maruyama
通讯作者：
Kouichi Maruyama

Effect of Heating Rate in α+γ Dual Phase Field on Lamellar Microstructure and Creep Resistance of a TiAl Alloy

α+γ双相场加热速率对TiAl合金层状组织和蠕变性能的影响

DOI：
发表时间：
2005
期刊：
Zeitschrift fur Metallkunde Vol.96, No.6
影响因子：
0
作者：
鳥山康成;Yasunari Toriyama;Yasunari Toriyama;Yasunari Toriyama;鳥山康成;Yasunari Toriyama;Hanliang Zhu;Hanliang Zhu;Hanliang Zhu;Hanliang Zhu;Hanliang Zhu;Hanliang Zhu;Kouichi Maruyama;Kouichi Maruyama;Hanliang Zhu;Kouichi Maruyama;Kouichi Maruyama
通讯作者：
Kouichi Maruyama

完全層状組織TiAl合金におけるα_2/γ界面への界面転位の導入と格子ミスフイット変化に及ぼすNbおよびZr添加の影響

Nb和Zr添加对全层状TiAl合金α_2/γ界面位错引入和晶格失配变化的影响