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

Ti-Al金属间化合物的压块是利用机械合金化（MA）制备的粉末生产的，机械合金化是最近开发的一种金属结合新技术，在本研究中，研究了其结构和机械性能，重点是它们的高性能。首先，作为本研究的基础，MA 加工粉末的小压块具有 Ti-50at%Al [TiAl(gamma) 单相]、Ti-30at%Al 几种标称成分通过真空热压制备了[Ti_3Al(α_2)单相]、Ti-40at%Al和Ti-45at%Al(γ+α_2)两相)，并通过压缩试验检查了它们的组织和机械性能。 ，推测MA加工粉末制成的压坯表现出超塑性变形行为，然后，我们打算通过将热等静压制成的较大压坯作为拉伸变形试验来进行进一步的研究。 MA 处理的粉末。制备并提供了典型两相合金的 MA ... More -HIPed 压块，(1) Ti-45at%Al 和所谓的富钛 TiAl 合金，(2) Ti-48at%Al使用 TEM 并结合能量色散 X 射线 (EDX) 分析设备进行 X 射线衍射和分析 TEM 观察。压块由两相 (gamma+alpha_2) 结构组成，且由完全超细等轴晶结构组成（压坯（1）和（2）的平均晶粒尺寸d分别为1.2和0.9μm），压坯（1）和（2）表现出最大的伸长率。在 1273K 和初始应变率 epsilon_i=1.4x10^<-4>s^<-1> 时达到 405% 的失效值，在 1273K 和初始应变率下达到 549% 的失效值1323K 和 epsilon^^·_i=5.6x10^<-3>s^<-1> 分别具有较高的应变率，即，除了这些事实之外，它们还表现出典型的超塑性行为。 ，Q_c，根据压坯应变率变化测试结果计算得出的恒定应力 (2)，n=2（n 是应力指数，应变率灵敏度指数， m=1/n)范围在高温(1173-1323K)和相对较高的epsilon范围(5.6x10^<-4>到2.0x10^<-2>s)下为350kj/摩尔，根据该压坯稳态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，得出结论：由MA处理粉末制成的超塑性富钛TiAl HIPed压坯（标称化学成分=Ti-48at%Al），在n=2范围内，是由最慢移动的晶格扩散控制的滑移所调节的晶界滑动因此，我们提出 Q_c 对应于最慢移动物质的晶格扩散活化能 Q_L 为 350kj/mole。

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。”

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

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。”

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）。

宇野 均,飴山 惠,時実 正治: "TiAl MA材の機械的性質におよぼす結晶粒径の影響" 日本金属学会講演概要(第109回). 333 (1991)

Hitoshi Uno、Kei Ameyama、Masaharu Tokizane：“晶粒尺寸对 TiAl MA 材料机械性能的影响”日本金属学会讲座摘要（第 109 期）（1991 年）。