Determination of Phase Equilibria by Experiment of Calonlation in F-Al-X Ternary System

F-Al-X三元体系相平衡实验测定

• 批准号: 07650811
• 负责人: TAKEYAMA Masao
• 金额: $ 1.41万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650811/
• 关键词: Till; Phase equilibria; Lattice stability; Transition peritectaid; Ternary entectic; Phase stability; 相安定性; マッシブ変態; 包共析反応; 組織制御; γ-TiAl; α_2-Ti_3Al; 3相共存領域; 冷却速度

Phase equilibria among the beta (bcc or B2), alpha (hcp) and gamma (L1_0) phases in Ti-Al-M ternary systems at elevated temperatures have been studied, where the M is beta stabilizing element for pure titanium. The beta (B2) +alpha+gamma three-phase coexisting region exists at temperatures above 1473 K,and it moves towrds a direction of high aluminum and high M concentrations with increasing temperature. The change in the phase equilibria by the addition M is associated with the alpha<tautomer>beta allotropic transformation temperature of pure titanium and can be thermodynamically interpreted in terms of the lattice stability ratios LAMBDA of M to Ti. The LAMBDA for beta against alpha in ternary Ti-Al-M systems, for example, is defined as follows : LAMBDA^<beta*alpha>_i=DELTAﾟG^<beta*alpha>_/DELTAﾟG^<beta*alpha>_. The DELTAﾟG^<beta*alpha>_ refers to the difference in Gibbs free energy between bcc (beta) structure and hcp (alpha) structure for pure M, and DELTAﾟG^<beta*alpha>_ that for … More pure titanium. The values of LAMBDA^<beta*alpha>_i for each element is nearly equal to 10 and at least one oeder of magnitude larger than those of LAMBDA^<alpha*gamma>_i. The reason the LAMBDA^<beta*alpha>_i has a large positive value for each element is that the value of DELTAﾟG^<beta*alpha>_ is fairly smaller than that of DELTAﾟG^<beta*alpha>_, since the temperature to be interest is only 300 K away from the beta*alpha allotropic transformation temperature T^<beta/alpha>_ (1155 K) of pure Ti. When the temperature raises and the difference in temperature from the T^<beta/alpha>_ becomes large, the value of DELTAﾟG^<beta*alpha>_ almost remains unchanged whereas that of DELTAﾟG^<beta*alpha>_ increases, leading to a smaller value of LAMBDA^<beta*alpha>_i. This is responsible for the three-phase coexisting region moving toward the direction of high aluminum and high M concentration as temperature increases.At the temperature below the alpha<tautomer>alpha_2 congruent temperature T^b_ in the binary system (T^b_ : 1452K), alpha_2-Ti_3aL phase appears as a stable phase as well, together with the other three phases. We identified that the beta+alpha+gamma three-phase coexisting region at higher temperatures changes to beta+alpha_2+gamma three-phase coexisting region at lower temperatures through a transition peritectoid reaction (beta+alpha<tautomer>alpha_2+gamma) when the thrid element M stablizes the alpha_2 phase against alpha phase. Less

在升高温度下，β（BCC或B2），α（HCP）和γ（L1_0）相之间的相等相等的相位已研究，其中M是纯钛的β稳定元件。 Beta（B2） +Alpha +Gamma三相共存区域存在于1473 K以上的温度下，并且随着温度升高，它移动了高铝和高M浓度的方向。添加m通过纯钛的α<automer>ββββ型β型含量转化温度与纯钛的α<automer> beta相关的变化，并且可以用M与Ti的晶格稳定性比率lambda lambda lambda lambda lambda lambda。例如，在三元ti-al-m系统中针对Alpha的beta的lambda定义如下：lambda^<beta*alpha> _i = delta = delta g^g^<beta*alpha*alpha> _/deltaﾟg^g^g^<beta*beta*alpha*alpha> _ _。 deltaﾟg^<beta*alpha>是指纯M的BCC（beta）结构与HCP（Alpha）结构之间的Gibbs自由能的差异，以及Delta ﾟ g^g^<beta*alpha> _，对于…更纯净的钛。每个元素的lambda^<beta*alpha> _i的值几乎等于10，至少一个比lambda^<alpha*gamma> _i大的偏度级。 The reason the LAMBDA^<beta*alpha>_i has a Large positive value for each element is that the value of DELTAﾟG^<beta*alpha>_ is fairly small than that of DELTAﾟG^<beta*alpha>_, since the temperature to be interesting is only 300 K away from the beta*alpha allotropic transformation temperature T^<beta/alpha>_ (1155 k）纯ti。当温度升高和温度差异与T^<beta/alpha> _变大时，delta ﾟ g^<beta*alpha> _的值几乎保持不变，而DeltaﾟG^<beta*alpha*alpha> _的值则增加了，导致Lambda^<Beta <beta*alpha*alpha> __i的价值较小。这是导致三相共存的区域朝着高铝和高浓度的方向移动。我们确定，在较高温度下，β+alpha+伽玛在较高的温度下与β+alpha_2+伽玛的变化变化，在较低温度下通过过渡角型反应（β+alpha+alpha <tautomer> alpha_2+gamma）在较低的温度下进行了反应，而Alpha_______________则在螺纹元素阶段时反对Alpha_2阶段。较少的

项目成果

M.Takeyama, M.Horikoshi, Y.Ohmura and T.Matsuo: "Decomposition of High-temperature alpha Phase in Gamma TiAl Alloy" Proc.Int.Conf.on Thermec '97, TMS. Vol.2. 148-1496 (1997)

M.Takeyama、M.Horikoshi、Y.Ohmura 和 T.Matsuo：“γ TiAl 合金中高温 α 相的分解”Proc.Int.Conf.on Thermec 97，TMS。

M.TAKEYAMA et al.: "Phase equilibria among α,α_2,β and γ phases in ternary Ti-Al-X systems at elevated temperatures" Titanium 95,Science and Technology,The Institute of Materials. 294-301 (1996)

M.TAKEYAMA 等：“高温下三元 Ti-Al-X 体系中 α、α_2、β 和 γ 相的相平衡”Titanium 95，科学与技术，材料研究所 294-301 (1996)。

竹山雅夫 他1名: "γ-TiAl合金における相平行と組織形成-Ti-Al 2元系合金に及ぼす大3元素の影響-" まてりあ,日本金属学会報. 35-10. 1058-1064 (1996)

Masao Takeyama 等 1：“γ-TiAl 合金中的相平行性和结构形成 - 三种主要元素对 Ti-Al 二元合金的影响”，日本金属学会通报 35-1064。 ）

T.Matsuo, O.Takahashi and M.Takeyama: "Stress and Temperature Dependence of Creep Rate in gamma-TiAl Single Phase Alloy" Proc.Int.Conf.on Thermec '97, TMS. Vol.2. 1465-1471 (1997)

T.Matsuo、O.Takahashi 和 M.Takeyama：“γ-TiAl 单相合金中蠕变速率的应力和温度依赖性”Proc.Int.Conf.on Thermec 97，TMS。

M.Takeyama, Y.Katho and M.Kikuchi: "Phase Equilibria among alpha, alpha_2, beta and gamma Phases in Ternary Ti-Al-X Systems at Elevated Temperatures" Titanium 95, The Institue of Metals. Vol.1. 294-301 (1996)

M.Takeyama、Y.Katho 和 M.Kikuchi：“高温下三元 Ti-Al-X 系统中 α、α_2、β 和 γ 相之间的相平衡”Titanium 95，金属研究所。