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; solidification reaction; precipitation reaction; MC decomposition reaction 中国科学院金属研究所高温合金和金属间化合物研究组50年来先后研究了高温合金中发生的各种相变.重点研究了凝固过程中发生的相变,沉淀反应,沉淀强化相的转变和碳化物相的转变. 1 凝固过程中发生的相变 1.1 L→(γ +Laves)共晶 郭建亭...-NiAl phases precipitated in iron-base superalloy with Ti/Al mass ratio of 0.5 (Main composition in mass fraction is Al 4.34%, Ti 2.18%, Cr 14.30%, Ni 34.88%, W 1.84%, Mo 2.15%, C 0.08%, B 0.015%, Ce......
Competition Growth of α and β Phases in Ti-50 at.%Al Peritectic Alloy during the Rapid Solidification by Laser Melting TechniqueWenjing YAO1,Xiuling NIU1,Long ZHOU1,Nan WANG1,Jehyun LEE21. The Key... and Components, Changwon National University,92 Toechon-ro, Uichang-gu Changwon-si摘 要:Rapid solidification of Ti-50 at.%Al peritectic alloy is realized......
in engineering. The addition of β-stabilizers, such as Nb, broadens the high-temperature β phase region towards the high Al composition side [9]. The peritectic solidification occurs during the DS... H Z. Microstructure selection during the directionally peritectic solidification of Ti-Al binary system [J]. Intermetallics, 2005, 13(3-4): 267-274. [25] DING X F, LIN J P, ZHANG L Q, SU Y Q, CHEN G L......
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Institute Group摘 要:The effect of Al content on the microstructure and solidification characteristics of Ti–Al–Nb–V–Cr alloys in as-cast and isothermally... coarse dendrites in the as-cast Ti47Al7Nb2.5V1.0Cr(at%) alloy solidifying through the peritectic reaction. The b-solidifying Ti46Al7Nb2.5V1.0Cr(at%) alloy with the narrow crystallization temperature range......
Metall Mater, 1994, 42(9): 2937-2441. [14] BA Fa-hai. Phase composition and kinetics study of rapid solidification Ni-Al alloy [D]. Beijing: University of Science and Technology Beijing, School... is suppressed; otherwise, φ phase preferentially forms while τ phase is suppressed. Key words: ZA84 alloy; silicon; phase selection; solidification kinetics 1 Introduction At present, the Mg-Al system alloys......
包晶合金定向凝固过程中的对流效应及带状组织形成机制 Ⅰ.实验结果骆良顺1,2,张宇民1,苏彦庆2,王新2,郭景杰2,傅恒志2(1.黑龙江省哈尔滨市哈尔滨工业大学材料科学与工程学院2.黑龙江省哈尔滨市哈尔滨工业大学特种环境复合材料技术国防科技重点实验室)摘 要:利用电阻加热和感应加热Bridgman定向凝固系统对非小平面包晶系模型合金Fe-Ni合金进行系统的定向凝固实验研究,探索2种常规定向凝固条件下对流对包晶合金定向凝固过程中带状组织和宏观偏析的影响规律.发现在高G/V定向凝固过程中,对流使包晶合金定向凝固过程中轴向和径向形成严重的宏观偏析,从而使组织演化异常复杂且难以达到稳态.轴向宏观偏析体现在有限长试样从定向凝固开始至凝固结束都将发生初生相向包晶相的转变过程,转变过程受合金成分和对流强度影响.径向宏观......
包晶合金定向凝固过程中的对流效应及带状组织形成机制 Ⅱ.理论分析骆良顺1,2,傅恒志1,张宇民2,李新中2,苏彦庆2,郭景杰2(1.黑龙江省哈尔滨市哈尔滨工业大学材料科学与工程学院2.黑龙江省哈尔滨市哈尔滨工业大学特种环境复合材料技术国防科技重点实验室)摘 要:本文分别利用纯扩散模型,溶质边界层对流模型和强对流Scheil方程对包晶合金定向凝固过程中的带状组织,宏观偏析的形成规律以及对流效应进行系统研究,详细讨论了对流对包晶合金定向凝固过程中带状组织和宏观偏析的影响规律.与Fe-Ni包晶合金定向凝固实验结果进行对比发现,对流强度参数λ在1.7至2之间时溶质边界层对流模型预测结果与感应加热定向凝固实验结果吻合很好,说明利用该模型可以预测对流较大条件下包晶合金定向凝固过程中的组织演化和轴向宏观偏析......
kave S(kiave, the average value of the ki across the whole stages of solidification)decreased monotonically, whereas kave Cincreased linearly. The peritectic reaction impacted on the phase composition and ki, leading to the change in microsegregation. Such effect of the peritectic reaction was more significant at the last stage of solidification. When the Pδ was between 75% and 100%(corresponding......
[7-17]. Seed making is a key step in controlling the structure of TiAl-based alloys in directional solidification. There are several seed making methods developed by LEE et al[10]. The method.... Fig.1 shows a binary phase diagram of Ti-Al alloy[7]. It can be seen that if the composition is lower than that of the peritectic point C1, the β-phase will form in the seed during the remelting......