Study on the Production of Ti-rich TiAl Compact and its Structure and Mechanical Properties.

富钛TiAl复合体的制备及其结构和力学性能的研究。

• 批准号: 03452251
• 负责人: TOKIZANE Masaharu
• 金额: $ 3.14万
• 依托单位: Ritsumeikan University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03452251/
• 关键词: Tial (gamma); Ti_3 Al (alpha2); Mechanical Alloying; Vacuum Hot Pressing; HIPing; Superplasticity; Activation Energy for Creep; Activation Energy for Lattice Diffusion; Ti_3Al(α_2); メカニカルアロィング; HIP焼結体; 等軸微細二相混合組織; Tiーrich TiAl金属間化合物; [TiAl(γ)

The compacts of Ti-Al intermetallic compounds were produced utilizing the powders prepared by mechanical alloying (MA) which has been recently developed as a new technique for combining metals. In the present study, the structure and mechanical properties were investigated, focusing on their high temperature workability.First of all, as the bases of the present study, the small compacts of MA-processed powders having the several nominal compositions of Ti-50at%Al [TiAl(gamma) single phase], Ti-30at%Al [Ti_3Al(alpha_2) single phase], Ti-40at%Al and Ti-45at%Al (gamma+alpha_2) two-phase) were produced by vacuum hot pressing, and examined their structure and mechanical properties by compression tests. From these results, it was presumed that the compacts made from MA-processed powders exhibit superplastic deformation behaviors. Then, we intended to carry out the farther study by tensile deformation tests by making the larger compacts made by HIPing the similarly MA-processed powders.The MA … More -HIPed compacts of a typical two-phase alloys, (1) Ti-45at%Al and so called Ti-rich TiAl alloy, (2) Ti-48at%Al, were prepared and offered to the X-ray diffraction and analytical TEM-observation using TEM accompanied by energy dispersive X-ray (EDX) analysis equipment. The compacts were consisted of the two-phase (gamma+alpha_2) structure, and composed of the fully ultra-fine equiaxed grain structure ( average grain size, d, of the compacts (1) and (2) were 1.2 and 0.9mum, respectively). The compacts (1) and (2) showed the maximum elongation to failure values of 405% at 1273K and the initial strain rate, epsilon_i=1.4x10^<-4>s^<-1>, and 549% at 1323K and epsilon^^・_i=5.6x10^<-3>s^<-1> which is comparatively higher strain rate, respectively. Namely, they showed typical superplastic behaviors. In addition to these facts, the activation energy of the creep, Q_c, at constant stress calculated from the results of the strain-rate-change tests of the compacts (2), in n=2 (n is the stress exponent, and strain rate sensitivity exponent, m=1/n) range of the present study, was 350kj/mole at high temperature (1173-1323K) and relatively higher epsilon range (between 5.6x10^<-4> to 2.0x10^<-2>s). Furthermore, the value of grain exponent, p, obtained from the grain size dependency of the steady creep rate of this compact was determined to be 2. Therefore, it concluded that the deformation mechanism of the superplastic Ti-rich TiAl HIPed compact (nominal chemical composition=Ti-48at%Al) made by the MA-processed powder), in the n=2 range, is grain boundary sliding accommodated by slip controlled by lattice diffusion of the slowest moving species in the Ti-Al phase. Thus, we proposed that the value of Q_c correspond to the activation energy for lattice diffusion, Q_L, of the slowest moving species is to be 350kj/mole. Less

利用机械合金化（MA）技术制备了Ti-Al金属间化合物压坯。首先，以Ti-50at%Al [TiAl（γ）单相]、Ti-30at%Al [Ti_3Al（α_2）单相]、Ti-30at%Al [Al_2O_3单相]、Ti-30at%Al [采用真空热压工艺制备了Ti-40at%Al和Ti-45at%Al（γ + α 2）两相合金，并通过压缩试验研究了其组织和力学性能。从这些结果中，可以推测，由MA处理的粉末制成的压坯表现出超塑性变形行为。然后，我们打算进行进一步的研究，通过拉伸变形试验，使较大的压坯由HIP类似的MA处理的粉末。 ...更多信息 制备了典型的两相合金（1）Ti-45at%Al和所谓的富Ti TiAl合金，（2）Ti-48at%Al的热等静压压坯，并使用TEM和能量色散X射线（EDX）分析设备进行了X射线衍射和分析TEM观察。压坯由两相（γ + α_2）组织组成，并由完全超细等轴晶组织组成（压坯（1）和（2）的平均晶粒尺寸d分别为1.2和0.9 μ m）。压坯（1）和（2）在1273 K和初始应变速率为1.4x10^ s^时的最大断裂伸长率分别为405%<-4><-1>，在1323 K和相对较高的应变速率为5.6x10^<-3>s^<-1>时的最大断裂伸长率分别为549%。即表现出典型的超塑性行为。此外，本文还根据压坯（2）在n=2时的应变率变化试验结果，计算了恒应力下的蠕变激活能Q_c（n为应力指数和应变速率敏感指数，m=1/n）在本研究的范围内，在高温（1173- 1323 K）和相对较高的温度范围（5.6 × 10 ~（-3）<-4>-2.0 × 10 ~（-3）<-2>s）下，此外，从该压块的稳定蠕变速率的晶粒尺寸依赖性获得的晶粒指数p的值被确定为2。因此，可以得出结论，由MA处理的粉末制成的超塑性富Ti TiAl HIP压坯（名义化学成分=Ti-48at%Al）在n=2范围内的变形机制是由Ti-Al相中最慢移动物种的晶格扩散控制的滑移调节的晶界滑移。因此，我们提出，与最慢运动粒子的晶格扩散激活能Q_L相对应的Q_c值为350 kJ/mole。少

项目成果

M.Tokizane,Y.Takaki,N.Ameyama: "Superplastic TiAl-Ti_3Al two-phase compact Made from Mechanically Alloyed podwer." ADVANCES in Powder Metallurgy & Particulate Materials-1992,Compiled by J.M.Capus and Randall.M.German.7. 315-323 (1992)

M.Tokizane、Y.Takaki、N.Ameyama：“由机械合金粉制成的超塑性 TiAl-Ti_3Al 两相致密体。”

Masaharu Tokizane,Hitoshi Uno and Key Ameyama: "Superplastic Behavior of ti-48at%al two-phase Titanium Aluminides Compact Made From Mechanically Alloyed Powder." The 3rd IUMRS International Conference on Advanced Materials,Sunshin City.Ikebukuro,Tokyo,Jap

Masaharu%20Tokizane、Hitoshi%20Uno%20and%20Key%20Ameyama:%20“超塑%20Behavior%20of%20ti-48at%al%20two-phase%20Titanium%20Aluminides%20Compact%20Made%20From%20Mechanically%20Alloyed%20Powder。”

M.Tokizane T.Takaki and K.Ameyama: "Superplastic TiAl-Ti_3Al Two-Phase Compact Made From Mechanically Alloyed Powder" “Norel Pcwder Processing"ADVANCES in Powder Metallugy & Paticulate Materidls-1992,Eli.by J.M.Capus,R.M.German.Proceedings of the 1992,Pow

M.Tokizane T.Takaki 和 K.Ameyama：“由机械合金粉末制成的超塑性 TiAl-Ti_3Al 两相压坯”“Norel Pcwder 加工”粉末冶金和颗粒材料的进展 - 1992 年，Eli.by J.M.Capus，R.M.German。 1992年学报，Pow

K.Ameyama,A.Miyazaki and M.Tokizane: "Superplastic Deformation Behavior of Mechanically Alloyed TiAl-Ti_3Al Intermetallic Compounds." “Superplasticity in Advdnced Materials"Edi.by S.Hori,M.Tokizane and N.Furushiro,Praceedings of an International Conferenc

K.Ameyama、A.Miyazaki 和 M.Tokizane：“机械合金化 TiAl-Ti_3Al 金属间化合物的超塑性变形行为”。

多加喜 義得,飴山 惠,時実 正治: "MAーHIP法によるTiー45at%Al焼結体の超塑性" 日本金属学会講演概要(第109回). 355 (1991)

Yoshitoshi Takagi、Kei Ameyama、Masaharu Tokizane：“MA-HIP 方法的 Ti-45at%Al 烧结体的超塑性”日本金属学会讲座摘要（第 109 期）（1991 年）。