Development of fundamental processes of directional solidification of TiAl-base Alloy

TiAl基合金定向凝固基本工艺研究进展

• 批准号: 13355027
• 负责人: YAMAGUCHI Masaharu
• 金额: $ 32.12万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13355027/
• 关键词: Directional solidification; Seeding; TiAl-base alloys; Lamellar microstructure; Mechanical properties; Constraint deformation; TiAl合金; 一方向凝固プロセス; 一方向凝固合金; 組織制御; クリープ強度; 凝固条件; 層状(ラメラ)組織; 拘束変形; 強度; 延性

Mechanical properties of the lamellar microstructure of TiAl-base alloys are extremely anisotropic with respect to the lamellar orientation. However, if the lamellar microstructure can be aligned parallel to the growth direction, the resulting material should possess a good combination of mechanical properties. The seeding and directional solidification (DS) techniques were developed for the lamellar boundaries to be aligned parallel to the growth direction. The lamellar structure of a wide variety of TiAl-base alloys can be controlled using the techniques. DS ingots of these alloys exhibit an excellent combination of room temperature tensile properties and high temperature strength, in particular, creep strength. Attempts were made to increase the size and growth rate of DS ingots for larger-scale production of TiAl castings through seeding and directional solidification. In order to obtain information on the mechanical behavior of DS ingots under the state of stress with multi-components, compression tests of DS ingots with various lamellar orientations were made under the constraint imposed along a direction perpendicular to the loading axis. Such constraint was found to significantly increase the yield stress of DS ingots with intermediate lamellar orientations. Slip systems which operate under the constraint were examined and the results were found to be in good agreement with those of the deformation analysis based on the description of anisotropic elastic continuum.

TiAl 基合金层状微观结构的机械性能在层状取向方面具有极大的各向异性。然而，如果层状微观结构可以平行于生长方向排列，则所得材料应具有良好的机械性能组合。晶种和定向凝固（DS）技术的开发是为了使层状边界平行于生长方向对齐。使用这些技术可以控制各种 TiAl 基合金的层状结构。这些合金的 DS 铸锭表现出室温拉伸性能和高温强度（特别是蠕变强度）的优异组合。人们尝试通过晶种和定向凝固来增加 DS 铸锭的尺寸和生长速率，以大规模生产 TiAl 铸件。为了获得DS铸锭在多组分应力状态下的力学行为信息，在垂直于加载轴方向的约束下，对不同层状取向的DS铸锭进行了压缩试验。发现这种约束显着增加了具有中间层状取向的 DS 铸锭的屈服应力。对约束下运行的滑移系统进行了检验，发现结果与基于各向异性弹性连续体描述的变形分析结果非常吻合。

项目成果

M.Yamaguchi et al.: "Directional Solidification of TiAl Based Alloys Using a Polycrystalline Seed"Materials Science & Engineering. A329-331. 25-30 (2002)

M.Yamaguchi 等人：“使用多晶晶种定向凝固 TiAl 基合金”材料科学

S.E Kim, Y.T.Lee, M.H.Oh, H.Inui, M.Yamaguchi: "Directional Solidification of TiAl Base AIloys Using a Polycrystalline Seed"Materials Science & Engineering. A329-331. 25-30 (2002)

S.E Kim、Y.T.Lee、M.H.Oh、H.Inui、M.Yamaguchi：“使用多晶晶种定向凝固 TiAl 基合金”材料科学

M.Yamaguchi: "Deformation and fracture of PST crystals and directionally solidified ingots of TiAl-base alloys"Materials Structure and micromechanics of fracture (MSMF-3), ASM International -Czech Chapter. 100-109 (2001)

M.Yamaguchi：“PST 晶体和 TiAl 基合金定向凝固锭的变形和断裂”材料结构和断裂微观力学 (MSMF-3)，ASM 国际 - 捷克分会。

H.A.Galderon: "Mechanical properties of nanostructured intermetallic alloys in the systems TiAl-X and Ti3Al-X"Structural Intermetallics 2001, TMS. 683-692 (2001)

H.A.Galderon：“TiAl-X 和 Ti3Al-X 系统中纳米结构金属间合金的机械性能”《结构金属间化合物》2001 年，TMS。

V.Paidar: "Compatibility stress in bicrystals of Polysynthetica11y twinned TiAl"Mater. Sci. Eng. A. 319-321. 332-336 (2001)

V.Paidar：“Polysynthetica11y 孪晶 TiAl 双晶中的相容性应力”材料。