Improvement of Room Temperature Ductility of Ti-40 50 at%Al Alloys through Microstructural Controll by Heat Treatment

改进%20of%20房间%20温度%20延展性%20of%20Ti-40%2050%20at%Al%20合金%20通过%20微观结构%20控制%20by%20加热%20处理

• 批准号: 02452243
• 负责人: KIKUCHI Makoto
• 金额: $ 4.29万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-02452243/
• 关键词: Titanium Aluminides; gamma; alpha_2 Lamellar Structure; Primary Lamellar Structure; Corsened Lamellar Structure; Discontinuous Corsening; 一次微細層状組織; 不連続粗大化層状組織; ドメイン; 逆位相境界エネルギ-

It has been commonly accepted that a microstructure consisting of gamma/ alpha_2/gamma lamellae improves the ductility of gamma titanium aluminides. In this program, we have established that there are two formation mechanisms of gamma/alpha_22/gamma lamellar microstructures, which we proposed to call as primary lamellar microstructure : P-LMS and discontinuously corsened lamellar microstructure : DC-LMS.1)Primary gamma/alpha_2/gamma lamellar microstructure : P-LMSFormation of the primary gamma/alpha_2/gamma lamellar microstructure was investigated using a Ti-40at%Al binary alloy. Upon quenching a disordered hcp alpha phase, stable at higher temperatures, to gamma+ alpha_2 two phase region, ordering from alpha to alpha_2 took place first, followed by precipitation of gamma plates on the basal plane of the alpha_2 matrix as a habit plane. Rapid lengthening of the gamma plates along the only one existing habit plane resulted in a seemingly perfect planar layer alignment of gamma and alpha_2 alternate lamellae. Variant distribution in the gamma plates was experimentally determined. Relative orientation relationships were discussed among independently grown gamma plates.2)Discontinuously corsened gamma/alpha_2/gamma lamellar microstructure : DC-LMS.Discontinuous coarsening(DC)of the P-LMS was studied in a temperature range between 1073 and 1473 K, using four Ti-Al binary alloys containing between 40 and 47 at%Al. DC started from the original alpha grain boundary. The migration rate of the advancing front of DC decreased with reaction time. The finer intelamellar spacing of P-LMS enhanced, while the larger volume fraction of alpha_2 phase beyond 50 pct in P-LMS inpeded, DC. DC divided a primary lamellar domain, whose size is the same as the original alpha grain size, into smaller colonies, within which not only the interlamellar spacing of the lamellae was larger, but also their alignment was less planar.

人们普遍认为，由γ/ alpha_2/伽马层组成的微观结构可改善伽马钛铝制的延展性。 In this program, we have established that there are two formation mechanisms of gamma/alpha_22/gamma lamellar microstructures, which we proposed to call as primary lamellar microstructure : P-LMS and discontinuously corsened lamellar microstructure : DC-LMS.1)Primary gamma/alpha_2/gamma lamellar microstructure : P-LMSFormation of the primary使用TI-40AT％Al二元合金研究了γ/alpha_2/gamma层状微结构。淬灭无序的HCPα相，在较高温度下稳定至伽马+ alpha_2两个相区域，从alpha到alpha_2的订购是首先发生的，然后在Alpha_2 matrix的基底平面上沉淀出伽马板作为习惯平面。沿唯一一个现有的习惯平面的伽马板的快速延长导致了伽马和alpha_2替代薄片的看似完美的平面层比对。实验确定了伽马板中的变异分布。 Relative orientation relationships were discussed among independently grown gamma plates.2)Discontinuously corsened gamma/alpha_2/gamma lamellar microstructure : DC-LMS.Discontinuous coarsening(DC)of the P-LMS was studied in a temperature range between 1073 and 1473 K, using four Ti-Al binary alloys containing between 40 and 47 at%Al. DC从原始的Alpha晶界开始。 DC前进前端的迁移速率随反应时间降低。 P-LMS的较细胞间距更细，而在pcled，DC中，alpha_2相的较大体积分数超过50 pct。 DC将一个与原始α晶粒尺寸相同的主要层状结构域分为较小的菌落，其中不仅层间的层间间距更大，而且它们的对齐也较少。

项目成果

Makoto KIKUCHI and Yoko YAMABE: "Mechnism of Formation of Primary gamma/alpha_2 Lamellar Microstructure in Titanium Aluminides" Proc. Jpn. Inst. Met. Symp. Intermetallic Compounds. 815-819 (1991)

Makoto KIKUCHI 和 Yoko YAMABE：“钛铝化物中初生 gamma/alpha_2 层状微观结构的形成机制”Proc。

Yoko YAMABE and Makoto KIKUCHI: "Distribution of Variants in gamma Plates in Primary gamma/alpha_2 Lamellar Microstructure of a Ti-40at% Al Alloy" Mater. Sci. Eng.

洋子%20YAMABE%20和%20Makoto%20KIKUCHI:%20"分布%20of%20Variants%20in%20gamma%20Plates%20in%20Primary%20gamma/alpha_2%20Lamellar%20微观结构%20of%20a%20Ti-40at%%20Al%20Alloy"

Yoko YAMABE and Makoto KIKUCHI: "Evolution and Microstructure of gamma/alpha_2 Lamellar Microconstituent in Ti-Al Binary Alloys" Bulletin Jpn. Inst. Matals. 30[1]. 37-42 (1991)

Yoko YAMABE 和 Makoto KIKUCHI：“Ti-Al 二元合金中 gamma/alpha_2 层状微成分的演化和微观结构”，Bulletin Jpn。

山辺 容子,菊池 實: "TiAlにおけるγ/α_2/γ層状組織の生成過程と構造" 耐熱金属材料第123委員会研究報告. 31. 179-194 (1990)

Yoko Yamabe，Minoru Kikuchi：“TiAl中γ/α_2/γ层状结构的生成过程和结构”第123届耐热金属材料委员会研究报告31. 179-194（1990）。

Yoko YAMABE and Makoto KIKUCHI: "Evolution and Microstructure of gamma/alpha_2/gamma Lamellar Morphology in TiAl" Report 123rd Committee on Heat-Resisting Metals and Alloys. 31[2]. 179-194 (1990)

Yoko YAMABE 和 Makoto KIKUCHI：“TiAl 中 gamma/alpha_2/gamma 层状形态的演化和微观结构”第 123 届耐热金属和合金委员会报告。