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1.
贵金属三元及多元合金相图研究的新进展   总被引:1,自引:0,他引:1  
通过分析《贵金属合金相图数据库》中的资料,评述了目前世界上贵金属三元系合金相图的研究新进展,表明贵金属三元合金相图已成为贵金属合金相图研究的主要组成部分,三元系上的多元系合金相图的研究也取得了很大的进展,指出贵金属合金相图的研究与贵金属材料的研究与开发具有密切的关系。本文还介绍中国贵金属合金相图研究的情况。  相似文献   

2.
二元连续固溶体合金交互作用参数与相图的计算机预报   总被引:2,自引:0,他引:2  
郭进 《金属学报》1999,35(4):427-429
利用人工神经网络方法讨论了原子参数与二元合金相的交互作用参数的关系,并通过热力学原理与人工神经网络方法的结合计算了二元连续固定溶体合金相图,所计算的相图与实测相图符合得很好。  相似文献   

3.
中国贵金属合金相图研究现状概述   总被引:1,自引:1,他引:0  
何纯孝 《贵金属》1992,13(2):55-63
中国贵金属合金相图的研究工作自1980年以来发展迅速。主要工作集中在银合金相图和铂族金属合金相图的研究;预测并合成一些新的金属间化合物:对合金化元素在银中固溶度的亚稳扩展作了系列研究。近年来对贵金属—稀土合金相图研究特别受到重视。已研究的银合金相图包括:Ag-Cu-Me(Me=Al,Cu,In,P,Zr),Ag-Zr,Ag-Al-Sn和Ag-Sb-Sn系。在Ag-Cu-Zr三元系中发现了一个高硬度的三元中间相,成分为Cu_(66.6)Ag_(16.7)Zr_(16.7)。已研究的铂族金属合金相图包括Pd-RE(RE=Ce,Nd,Pr,RE≤50 at%),Pd-Gd-Me(M=Ag、Pt),Ru-Te及Os~-Ru-Te系。合成了一些新金属间化合物并测定它们的晶格常数,它们是:NdIr_3,GdIr_3,DyIr_3,SmPd_5,EuPd_5,PrPd_5,LaPd_5,RuTe_2,M-OsTe_2,GdPtIn_2及RuS·RuS_2·10H_2O。对Pt_(83.34)Cu_(16.66)研究确定,这种合金发生有序Spinodal分解。研究了微量Y在Pt中的固溶度。研究了三类合金化元素在银中固溶度的亚稳扩展,这些元素是:①简单金属,包括Al、Bi、Cd、Ga、Go、In、Pb、Sb、Sn、Zn;②稀土金属,包括Y,La、Ce、Pr、Nd、Sm、Gd、Tb、Dy、Er;③过渡金属,包括Fe、Co、Ni、Cr、Mn、Zr。讨论影响亚稳扩展的因素和相图类型的关系及规律。并出版了《贵金属合金相图》(中英文),和行将出版《贵金属合金相图第一补编》(中英文)。  相似文献   

4.
基于文献报导的实验数据,采用相图计算(CALPHAD)方法,热力学优化了Bi-Ni二元系相图。该二元系的液相、fcc_A1(Ni)相和rhombohedral_A7(Bi)相用替换溶液模型来描述,其过剩吉布斯自由能用Redlich-Kister多项式来表达。考虑到晶体结构(NiAs型)以及与多组元体系热力学数据库的兼容性,中间化合物BiNi相采用亚点阵模型:(Bi)(Ni,Va)(Ni,Va);Bi3Ni相处理为化学计量比化合物。最后,通过优化该二元系实测的相图和热力学数据,获得一组能够表达各相吉布斯自由能的自洽的热力学参数。根据这些热力学参数计算的相图和热力学数据与报导的实验数据吻合良好。  相似文献   

5.
以改进的“中心原子”模型计算Ag—Cu相图   总被引:1,自引:0,他引:1  
简化并推导了“中心原子”模型公式,使其在形式和参数意义上更接近普通热力学计算相图公式。在新模型中,A-B二元系合金第i个原子态Φ^αi状态量与组态Φ^α0的状态量之差(φ^αi-φ^α0)不必与(φ^α1-φ^φ0)成正比(i表示α原子周转最近邻有i个B原子),而各原子态Φ^αi在合金中存在的几率之和Pα等于α组元在合金中活度系数的倒数。采用修改后的“中心原子”模型公式计算Ag-Cu相图及热力学性  相似文献   

6.
三元合金的高温理论氧化图Ⅰ.高氧压下的近似分析   总被引:2,自引:0,他引:2  
牛焱  曹中秋  王文  吴维 《金属学报》2000,36(7):744-748
通过对三元合金系高温氧化行为的分析,把Wagner关于形成不互溶氧化物的二元合金经典理论扩展到三元合金体系,忽略活泼组元内氧化,以热力学稳定相图为参考,建立了相应的动力学氧化图并分析了影响动力学氧化图的因素,为进上步研究三元合金高温氧化行为提供了重要的理论依据。  相似文献   

7.
相图及其在钛电解新工艺和钛合金设计中的应用   总被引:1,自引:0,他引:1  
相图是材料设计的指导书、冶金工作者的地图和热力学数据的源泉。简要概述了近年来相图计算研究的进展,举例说明了Ti-C-O三元系及其亚二元系相图在钛电解新工艺研究中的应用及Ti-Al相图在钛合金设计中的应用,并在文献中列出了新的可靠的合金和化合物相图的来源。最后指出,进一步测定Ti-C-O三元系中TiC-TiO固溶体的精确固溶范围及其与其它相的相关系对于直接电解TiO2提取金属钛新工艺的工业化有重要意义。  相似文献   

8.
使用计算相图方法(CALPHAD)计算Au-Ag-Al的三元相图时,三个边际二元相图(Au-Al,Au-Ag,Ag-Al)的准确性对三元相图的计算有很大的影响,目前Au-Al边际二元相图存在着一定的矛盾。在综合评估Au-Al体系实验数据的基础上,优化和计算了Au-Al合金体系的平衡相图,使用置换式溶体溶液模型描述Au-Al体系中液相、Bcc和Fcc相的吉布斯自由能,分别用亚点阵模型(Al)(Au)4、(Al)3(Au)8、(Al)(Au)2、(Al)(Au)和(Al,Au)2(Al,Au)描述AlAu4、Al3Au8、AlAu2、AlAu和Al2Au相,通过Pandat软件优化得到一组各相的热力学参数,计算得到的Au-Al相图与实验数据和热力学数据相吻合。结合Au-Ag和Ag-Al的热力学参数,计算了Au-Ag-Al液相面投影图和等温截面图,液相面投影图显示该三元系存在8个四相平衡反应,对Au-Ag-Al合金的研究具有指导意义。  相似文献   

9.
本研究利用CALPHAD方法,采用合理的热力学模型,热力学优化和计算了Nd-Dy、Dy-B二元系和Fe-B-Dy、Dy-Fe-Nd、B-Dy-Nd三元系的相图,并利用文献报道的其他子二元系和三元系的热力学参数,充分考虑了热力学模型的统一性和参数的兼容性,建立了Nd-Fe-B-Dy四元系合金的热力学数据库,并应用该数据库,预测了Nd-Fe-B-Dy四元合金Nd16-xDyxFe77B7 (x≤5 at.%)的纵截面相图;同时还分析了一系列不同Dy含量的永磁合金在平衡凝固下各相相分数随温度的变化情况。这些计算信息对掺镝NdFeB永磁合金的组织设计以及制备工艺参数的选择具有重要的指导意义。  相似文献   

10.
用差热分析法测定YCl3-SrCl2体系二元相图,并用X射线衍射法验证了该二元体系中新相的生成。使用CALPHAD技术评估和优化了YCl3-AECl2(AE=Mg,Ca,Sr,Ba)系列四个二元相图和热力学性质,取得了热力学性质和相图自相结果。  相似文献   

11.
The relationship between the types of binary alloy phase diagrams of Vlll and IB group elements and the Men deleev numbers was discussed for the first time using the Vlll and IB group elements as solvent metals (A) and the other elements as solute metals (B), basesd on their alloy phase diagram types. The Mendeleev numbers of the solvent metals and the solute metals were expressed as Ma and MB, respectively. A two-dimension map of MdMB was drawn. It is indicated that there is an oblique line in the map, which divides the binary alloy phase diagram types of solvent metals into two symmetry parts, the phase diagram types of the other elements with solvent metals located at the above or down of the line respectively, while on the line, AM= 0. The phase diagrams between the solvent metals basically are simple systems, mainly belong to the types of continues solid solution and the peritectic (about 40% for each type). The solvent metals can be divided into three groups: Co, Ir, Rh, Ni, Pt, and Pd as the first group; Ag, Au, and Cu as the second group;and Fe, Os, and Ru as the third group. The characteristics of the phase diagrams formed between the elements in each group were discussed. About 80% phase diagrams belong to complex systems and less than 20% belong to the simple systems. The regular variation of the chemical scale, the metallic radii of the atoms, the number of valence electrons, and the first ionization energy with the Mendeleev numbers and the crystal structure were introduced as well.  相似文献   

12.
This paper presents a computer program for the calculation of the isothermal phase diagrams of quaternary systems involving sodium, a pure metal, oxygen and sulfur, which are useful for examining the experimental results concerning the hot corrosion of metallic materials. The procedures adopted to calculate the location of the points where four condensed phases are simultaneously present (quadruple points) and to draw the regions of stability of each phase containing the metal are presented by means of examples concerning a practical system. The nature of these quaternary phase diagrams is examined with reference to the various types of quadruple points and to their interconnections with lines of equilibrium involving the participation of three different phases. Examples of phase diagrams of some quaternary systems calculated by means of the present program are given.  相似文献   

13.
The effect of coupling with calculation of phase diagrams on microsegregation forming simulation was investigated. The traditional simplified phase diagram and calculated phase diagram were introduced into the numerical models respectively and simulation on microsegregation forming of the Al-4.5%Cu alloy ingot was also presented. The simulation results were both compared with the experiment results. The results show that the calculated sencondary arm spacing with these two kinds of phase diagram are almost the same because relationship between the coarsening model and the information of phase diagram is not close. The calculated eutectic phase volume fractions of different locations in the ingot coupled with different phase diagrams are discrepant. The calculated volume fractions are consistent with the experiment results when calculated phase diagram couples, but are far from the experiment results and obviously inacceptable when traditional simplified phase diagram couples. So, coupling with accurate calculated phase diagrams is very significant for microsegregation forming simulation since much information of the phase diagram is used in the models and it can improve the precision of simulation results.  相似文献   

14.
1.IntroductionAlthoughthecomputerizedpredictionofalloyphasediagramsbythermodynamicmethodhasmadegreatachievements,thelackofthermodynamicdataisoneoftheobstaclesforthecomputationofalloyphasediagrams.Manymethodsforcomputerizedalloyphasediagramshavebeenproposedinordertoovercometheobstacle.Forexample,thereareHume--Rotherytheory[']forsolidsolutiollofbinaryalloysystemandMiedema'stwoparameters.oded2](Ark*,A.;/sa)forthethermodynamicpropertyestimationofalloysystems.Che.[3--5]hajsappliedatomicparameter-…  相似文献   

15.
利用CALPHAD方法,采用亚正规溶体模型、亚点阵模型以及理想气体模型来描述RE-X(Ag,Bi,Cr,Mn,Mo,V,Zn)中二元系各相的Gibbs自由能,并结合相平衡及热力学性质的实验结果,对Ag-RE(RE:Sc,Y Nd,Sm,Gd,.Tb,Ho,Er)、Bi-RE(RE:Nd,Tm,Er,Ho,Pr,Gd)、...  相似文献   

16.
NEWMETHODSFORCALCULATINGACTIVITIESOFCOMPONENTSFROMPHASEDIAGRAMSINBINARYPERITECTICSYSTEMS①ZhangYongjunHunanSuperiorTechMateri...  相似文献   

17.
Gesmundo  F.  Niu  Y.  Wang  W. 《Oxidation of Metals》2001,56(5-6):537-549
The construction and the properties of three-dimensional diagrams showing the regions of stability of the various compounds, which can form as a result of the oxidation of ideal ternary A–B–C alloys by a single oxidant at a constant temperature (kinetics diagrams) are examined for oxidant pressures insufficient to oxidize all possible alloys within the system (low oxidant pressures). For the calculation it is assumed that the various oxides do not dissolve into each other and do not form double oxides and that the alloy has an ideal behavior, while internal oxidation of the most-reactive components is disregarded. The range of meaningful oxidant pressures is divided into six intervals, which correspond to the formation of different types of scales. The simplified two-dimensional (2D) kinetics diagrams presented are obtained by projecting the appropriate three-dimensional (3D) lines of equilibrium between the alloy and the various oxides on the base triangle, which gives the composition of the system in terms of the three metal components only. The kinetics diagrams are correlated with the corresponding equilibrium phase diagrams for the same quaternary A–B–C–O systems.  相似文献   

18.
Niu  Y.  Gesmundo  F. 《Oxidation of Metals》2001,56(5-6):517-536
The general properties of the isothermal thermodynamic phase diagrams for ternary A–B–C alloys exposed to a single oxidant at high temperatures are examined, assuming, for simplicity, the formation of insoluble p-type oxides, an ideal behavior of the alloy, and a common value of the self-diffusion coefficient for the alloy components, independent of the alloy composition, but disregarding the possibility of internal oxidation. Simplified two-dimensional phase diagrams are produced by projecting the lines and points of equilibrium of the complete three-dimensional diagrams on the base triangle, which gives the composition of the system in terms of the metal components only. Similar kinetics diagrams concerning the nature and the growth kinetics of the scales formed on ternary alloys as functions of the bulk substrate composition are also calculated for oxidant pressures above the stability of the oxides of all the alloy components and some of their general features are examined. The kinetics diagrams for ternary alloys exposed to a single oxidant contain seven regions, three of which correspond to the areas of stability of each single oxide, three to the possible mixtures of two oxides, and one to a mixture of all three oxides.  相似文献   

19.
利用CALPHAD方法,选择和建立合理的热力学模型,并结合相平衡及热力学性质的相关实验信息,对Mo-RE (RE: Ce, Pr, Nd, Sm, Eu, Tb, Ho, Er, Tm, Yb, Lu)各二元系相图进行了热力学优化与计算。其中,液相和端际固溶体相的Gibbs自由能采用亚正规溶体模型描述,气相的Gibbs自由能采用理想气体模型描述。计算结果与实验数据取得了良好的一致性,最终得到了一组自洽的合理描述Mo-RE二元系各相自由能的热力学参数,建立了Mo-RE (RE: Ce, Pr, Nd, Sm, Eu, Tb, Ho, Er, Tm, Yb, Lu)二元合金相图的热力学数据库。该热力学数据库可以提供相平衡及热力学性质等多种信息,为外推计算三元以及更多组元体系的相平衡提供理论基础,并为相关体系的合金设计及制备提供重要的理论指导。  相似文献   

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