杜勇
从事相图热力学、扩散动力学及材料设计的理论和实验研究工作
个性化签名
- 姓名:杜勇
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学术头衔:
博士生导师
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学科领域:
冶金工程技术
- 研究兴趣:从事相图热力学、扩散动力学及材料设计的理论和实验研究工作
杜勇,中南大学教授、博士生导师,国家杰出青年基金获得者。现任国际刊物CALPHAD(相图及热化学计算耦合杂志)副主编;德国金属学报(Z. Metallkd.,现改名为International Journal of Materials Research)编委;中国《金属学报》编委;国际相图委员会委员。杜勇教授自1986年开始从事相图热力学、扩散动力学及材料设计的理论和实验研究工作,做出了一些具有国际重大影响的科研成果。至2006年3月底,已在25种国际刊物上发表论文98篇(第一作者66篇),其中SCI收录87篇,SCI引用513次(他引452次)。中、美、俄、德、英、法、日等33国130个研究院所的科学家在75种国际刊物上广泛引用了杜勇等发表的论文。美、德出版的4种专著《Phase Equilibria Diagrams》、《Landolt-Boernstein》、《Ternary Alloys》和《Red Book》用多达189个版面收录了杜勇等发表的一系列研究结果。美国宇航局(NASA)科学家、欧洲尤里卡计划COST507项目的科学家,以及国际著名大公司(如美国GE公司、加拿大Teck Cominco Metals公司、瑞典Thermo-Calc公司等)在设计新型材料时多次采纳和引用杜勇等发表的研究成果。杜勇取得的主要学术成绩如下:
1. 建立了多组元陶瓷及金属体系相的热力学模型杜勇等首次将ZrO2基体系相的热力学与晶体结构相结合,综合考虑有序无序相变理论及晶体结构信息,用一个热力学模型描述多组元体系同一相的有序和无序状态,突破前人用两个热力学模型分别描述有序、无序状态的局限性。国际刊物《CALPHAD》杂志主编L. Kaufman教授称杜勇等提出的上述模型为杜-金模型,该热力学模型被欧洲热力学数据科学研究组织采纳,并推荐作为标准模型。
2. 提出了构筑多元相图的实验模拟互补法杜勇提出了一种构筑多元相图的创新方法:实验模拟互补法。审稿专家在评审他撰写的论文时写道“作者的研究工作提供了一种研究相平衡的创新方法,构筑了复杂体系相平衡数据库的核心,对材料科学的发展作出了非常重要的新贡献。此创新方法将作为未来研究工作的参照和样本”。
3. 提出了一种描述线性化合物扩散生长的新方法,建立了SiC,TiC基体系扩散动力学数据库线性化合物的扩散生长描述是前人一直没有解决好的问题。杜勇综合考虑热力学、扩散动力学及晶体结构信息,首次引入平均热力学因子,提出了一种描述线性化合物扩散生长的新方法。 2003年瑞典皇家工学院精选了三篇关于相互扩散的论文,并以报告及网络形式向国际学术界推荐,其中的一篇论文为杜勇所发表。
4. 首次提出了分步热力学优化方法并用于研究氮化物体系界面反应
5. 提出了预测杂质扩散系数新方法
6.提出了一种考虑界面能对自由能的贡献、科学设计硬质合金涂层的方法
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1189
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成果数
15
杜勇, F. Zhanga, *, Y.A. Changb, Y.Dub, S.-L. Chena, W.A. Oatesc
Acta Materialia 51(2003)207-216,-0001,():
-1年11月30日
The modified cluster-site approximation (CSA) model has been used to model the f.c.c. phases (ordered L12 and disordered A1) in the Ni-Al system. The CSA model has the advantage over the cluster variation method (CVM) in that the independent variables in the free energy functional are the site probabilities and not the cluster probabilities. Unlike the zeroth approximation, however, the CSA takes short-range order into consideration, an essential requirement for describing phases that undergo an order/disorder transition, as does the f.c.c. phase in the Ni-Al system. By using the modified CSA model, we have been able to obtain an improved phenomenological description of this system with the use of fewer model parameters than used in previous descriptions. The topology of the calculated metastable f.c.c. phase diagram is similar to the one obtained using a 'first-principles'-CVM approach, whereas the f.c.c. phase diagrams based on the previous phenomenological descriptions are unsatisfactory.
Cluster-site approximation, Nickel alloys, Phase diagrams, Order-disorder phenomena, Thermodynamics
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杜勇, Yong Dua, b, *, Y.A. Changb, Baiyun Huanga, Weiping Gonga, Zhanpeng Jina, Honghui Xua, Zhaohui Yuana, Yong Liua, Yuehui Hea, F.-Y. Xiec
Materials Science and Engineering A363(2003)140-151,-0001,():
-1年11月30日
The diffusion coefficients of several transition elements (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) and a few non-transition elements (Mg, Si, Ga, and Ge) in fcc and liquid Al are critically reviewed and assessed by means of the least-squares method and semi-empirical correlations. Inconsistent experimental data are identified and ruled out. In the case of the elements, for which plentiful experimental data are available in the literature, the least-squares analysis gives rise to the activation energies and pre-exponential factors in an Arrhenius equation. For the elements with limited experimental data or no data at all, the diffusion parameters are estimated from two semi-empirical correlations. In one correlation, the logarithmic pre-exponential factors are plotted against the activation energies for various elements in Al. In the other correlation, the activation energies are shown as a function of valences relative to Al. The diffusion coefficients calculated by using the evaluated diffusion parameters agree reasonably with the reliable experimental data. The proposed semi-empirical correlations are used to predict the diffusion coefficients of a few elements in liquid Al. A satisfactory agreement between the predicted and measured diffusion coefficients is obtained.
Aluminum alloys, Impurity diffusion coefficient, Semi-empirical correlations, Diffusion modeling
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【期刊论文】Thermodynamic properties of the Al-Nb-Ni system
杜勇, Yong Dua, b, *, Y.A. Changa, Weiping Gongb, Baiyun Huangb, Honghui Xub, Zhanpeng Jinb, F. Zhangc, S.-L. Chenc
Intermetallics 11(2003)995-1013,-0001,():
-1年11月30日
This paper provides a consistent thermodynamic data set for the whole Al-Nb-Ni ternary system via thermodynamic modeling. The order/disorder transitions between disordered bcc_A2 and ordered bcc_B2 phases as well as between disordered fcc-A1 and ordered L12 phases are treated using a two-sublattice model. The calculations indicate that the disordered and ordered phases can be described with a single equation. All of the experimental phase diagram data available from the literature are critically reviewed and assessed using thermodynamic models for the Gibbs energies of individual phases. Inconsistent experimental information is identified and ruled out. Optimal thermodynamic parameters are then obtained by considering reliable literature data. Comprehensive comparisons between the calculated and measured phase diagrams show that almost all the accurate experimental information is satisfactorily accounted for by the present thermodynamic description.
A., Ternary alloy systems, B., Phase diagram, B., Thermodynamic and thermochemical properties, B., Order/, disorder transformations, E., Phase diagram prediction
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【期刊论文】Thermodynamic assessment of the Mo-Nb-Ta system
杜勇, Wei Xiong, Yong Du*, Yong Liu, B.Y. Huang, H.H. Xu, H.L. Chen, Zhu Pan
Computer Coupling of Phase Diagrams and Thermochemistry 28(2004)133-140,-0001,():
-1年11月30日
Thermodynamic optimizations of the Mo-Nb, Mo-Ta, and Nb-Ta binary systems were performed by considering the experimental phase diagram and thermodynamic data available from the literature. The Mo-Nb-Ta ternary system was then synthesized from the descriptions of the binary sides. The calculated thermodynamic properties as well as phase diagrams for the binary systems agree well with the experimental ones. In the case of the ternary system, several isothermal sections were calculated by extrapolation from the three boundary systems. The model-predicted liquidus temperatures in the ternary system are in reasonable agreement with the experimental data. The computed liquidus projection and a set of model parameters describing the Gibbs energies of the assessed phases are also presented.
Mo-Nb-Ta system, Phase diagram, Thermodynamic calculation
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【期刊论文】thermodynamic description of the Al-Be system: Modeling and experiment
杜勇, Zhu Pan, Yong Du*, B.Y. Huang, Yong Liu, R.C. Wang
Computer Coupling of Phase Diagrams and Thermochemistry 28(2004)371-378,-0001,():
-1年11月30日
The Al-Be system is investigated via three steps. In the first step, all of the experimentally measured phase diagram and thermodynamic data available in the literature are critically reviewed. On the basis of the assessed phase diagram, in the second step, eight decisive samples are prepared by arc melting of Al and Be pieces and annealing at 600℃ for eight days. Water-quenched samples are analyzed using differential thermal analysis (DTA), X-ray diffraction (XRD), optical microscopy, and scanning electron microscopy (SEM) techniques. In the last step, an optimal thermodynamic data set for the Al-Be system has been obtained by considering the present experimental data and the reliable literature data. The calculated phase diagram and thermodynamic properties agree well with the accurate experimental values.
Al-Be phase diagram, Thermodynamic calculation, X-ray diffraction, Differential thermal analysis
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杜勇, YONG DU. JULIUS C. SCHUSTER, FRANZ WEITZER, NATALIYA KRENDELSBERGER, BAIYUN HUANG. ZHANPENG JIN, WEIPlNG GONG, ZHAOHUI YUAN, and HONGHUl XU
METALLURGICAL AND MATERIALS TRANSACTIONS A, VOLUME 35A. MAY 2004,-0001,():
-1年11月30日
A thermodynamic modeling for the A1-Mn-Si system is conducted via two steps. In the first step, all of the experimental phase diagram and thermodynamic data available from the literature ate Critically reviewed. and several isopleths are constructed by means of X-ray diffraction (XRD) and differential thermal analysis (DTA) techniques. In the second step, a consistent thermodynamic data set for the A1-Mn-Si system over the entire composition and temperature ranges is obtained by consideling reliable literature data and the present experimental results. Numerous comparisons between the calculated and measured phase diagrams as well as thermodynamic quantities indicate that almost all of the reliable experimental information is satisfactorily accounted for by the thermodynamic modeling. The liquidus projection and reaction scheme for the entire system are also presented.
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【期刊论文】Amorphous and nanocrystalline Al82Ni10Y8 alloy powder prepared by gas atomization
杜勇, Yong Liu*, Zuming Liu, Sheng Guo, Yong Du, Baiyun Huang, Jinsong Huang, Shiqi Chen, Fengxiao Liu
Intermetallics 13(2005)393-398,-0001,():
-1年11月30日
An Al-10Ni-8Y (at.%) alloy was atomized by Ar gas and the morphology, microstructure, thermal stability, phase composition and microhardness of the as-atomized powder were investigated. Most of the powders are spherical in shape, but the surface morphology was different for powder of different size. The cross-section microstructure of powder with size below 15mm in diameter showed no detailed feature, indicating existence of amorphous phase or nanocrystalline structure. The as-atomized powder showed four distinct exothermic peaks when heated at 296, 340, 366 and 456 8C. The glass transition temperature Tg, crystallization temperature Tx, and the temperature interval of the supercooled liquid region DTx (ZTxKTg) were detected to be about 266, 288 and 22 8C. The Al82Ni10Y8 alloy powder exhibits a high Vickers hardness of 230.6, and shows great potential for structural application.
B., Glasses,, metallic, B., Phase identification, C., Powder metallurgy, D., Microstructure
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杜勇, YONG DU*, J. C. SCHUSTER, Y. A. CHANG
JOURNAL OF MATERIALS SCIENCE 40(2005)1023-1025,-0001,():
-1年11月30日
rature five groups of authors [1, 2, 4, 6, 7] reported an eutectic reaction type (L→(Al)+Al45Cr7), whereas the remaining two groups [3, 5] suggested a peritectic one, L+Al45Cr7→(Al). In the phase diagram assessed by Murray [11, 12], the peritectic reaction type is adopted. The purpose of the present work is to identify the degenerated nature for the invariant reaction among (Al), liquid, and Al45Cr7 by means of differential scanning calorimetry (DSC), X-ray diffraction (XRD) and electron probe microanalysis (EPMA) methods
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【期刊论文】Isothermal section at 950℃ of the Co-Nb-Ti system
杜勇, Honghui Xua, *, Yong Dua, Chengying Tanga, Yuehui Hea, Zhaohui Yuana, Baiyun Huanga, Shitong Lib
Materials Science and Engineering A 412(2005)336-341,-0001,():
-1年11月30日
The isothermal section at 950℃ of the Co-Nb-Ti system was investigated using diffusion couples and six ternary alloys. The specimens were examined by means of optical microscopy, scanning electron microscopy and electron probe microanalysis. No ternary compound was found. Nine three-phase equilibria were observed. The binary intermediate phases NbCo3 and Nb2Co7, the existence of which is still controversial in the literature, were observed at 950℃. The solubilities of Ti in Nb2Co7, NbCo3, γ-NbCo2 and μ-Nb6Co7 were determined to be 1.9, 16.4, 14.4 and 17.4 at.%, respectively. The solubilities of Nb in TiCo3, TiCo2(h), TiCo2(c), TiCo and Ti2Co were determined to be about 5.7, 11.0, 2.6, 13.6 and 3.1 at.%, respectively.
Co-Nb-Ti system, Phase equilibrium, Diffusion couple, EPMA
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杜勇, Yong Dua, Y. A. Changb, Shuhong Liua, Baiyun Huanga, F.-Y. Xieb, Ying Yangb, S.-L. Chenb
Z. Metallkd. 96(2005)12,-0001,():
-1年11月30日
The thermodynamic database for the Al-Fe-Mg-Mn-Si system is developed based on the constituent binary, ternary, and quarternary systems. The computed phase diagrams agree well with the experimental data. The obtained database is used to describe the solidification behavior of Al 356.1 (91.95Al-0.46Fe-0.3Mg-0.32Mn-6.97Si, in wt.%) and Al 356.2 (92.77Al-0.08Fe-0.35Mg-6.8Si, in wt.%) under equilibrium and Gulliver-Scheil non-equilibrium conditions. The reliability of the established thermodynamic database is also verified by the good agreement between calculation and experiment for both equilibrium and Gulliver-Scheil non-equilibrium solidifications. Microstructure and microsegregation of the directionally solidified Al 356.1 alloy are investigated with a growth rate of 0.04445 cm s-1 and a temperature gradient of 45K cm-1. Fractions of solids formed are measured by using quantitative image analysis of back-scattered electron, and solute redistribution in the primary (Al) is determined by means of an area scan approach with a total of 2400 electron probe microanalysis point counts. A micromodel, which includes solid-state diffusion, secondary dendrite arm coarsening, and dendrite tip and eutectic undercooling, is coupled with a multicomponent phase diagram calculation engine (PanEngine) to predict the microstructure and microsegregation of the solidified alloy. Quantitative agreement of the model prediction with the experiment is obtained for concentration distributions in the primary (Al), the types and amounts of phases formed, and the solidification path.
Microstructure, Microsegregation, Electron probe microanalysis, Directional solidification, Micromodel, Al alloys
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