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Rare Metals 2022年第10期41卷 3552-3559页

作者： Xing-Chao Wu Yong-Sheng Li Wei Liu Zhi-Yuan Hou Meng-Qiong Huang School of Materials Science and Engineering Nanjing University of Science and TechnologyNanjing210094China

The precipitation dynamics of γ’(L1-nial)phase and composition interfacial width between γ(fcc ni)and γ’ phase were investigated using the phase field simulation linking with CalPHAD *** coarsening rate and particle size distribution(PSD) of γ’ phase,the temporal composition interfacial width of γ/γ’ in ni-17 at% al alloy aged at 923,973 and 1023 K were *** the aging temperature increases,the morphology of γ’ phase changes from the interconnected rectangle shape to the separated cuboidal *** average particle radius() of γ’ phase at coarsening stage follows ∞t^(n) with the exponents n=0.21,0.23 and 0.26,*** peak values of simulated PSDs at 923 K are less than the value calculated by the Lifshitz-Slyozov-Wagner(LSW) model,and the width of simulated PSD increases at later stage of *** normalized radius(r/)which corresponds to the peak value of PSD moves from1.1 to 1.0 as the aging temperature increases from 923 to1023 K,and they are smaller than that of LSW *** composition interfacial width decreases as the aging progresses and increases as the aging temperature increases.

关键词： ni-al alloy Precipitation Dynamics Particle size distribution Composition interface Phase field

Theoretical Calculation of the Real Vapor Pressure of al during ISM Processing of ni-xal (***) (x=25-50) alloy

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Journal of Materials Science & Technology 2004年第2期20卷 189-192页

作者： Jingjie GUO,Guizhong LIU, Yanqing SU, Jun JIA and Hengzhi FUSchool of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China Sch. of Mat. Sci. and Eng. Harbin Inst. of Technol. Harbin 150001 China

A new model was established to calculate the real vapor pressure of al in the molten ni-xal （***）（x=25;0） alloy. The effects of the holding time, chamber pressure, mole fraction of al and melting temperature on the real vapor pressure of al in the vacuum chamber were analyzed. Because of the impeding effect of the real vapor pressure on the evaporation loss rate, within a short time （less than 10 s）, the real vapor pressure tends to a constant value. When the chamber pressure is less than the saturated vapor pressure of al, the real vapor pressure of al is equal to the chamber pressure. While when the chamber pressure is higher than the saturated vapor pressure, the real vapor pressure of al approaches to the saturated vapor pressure of al of the same condition.

关键词： Real vapor pressure Volatile elements ISM process ni-al alloy

Density of ni-al alloys in Liquid and Solid-Liquid Coexistence State Measured by a Modified Pycnometric Method

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Journal of Materials Science & Technology 2004年第4期20卷 405-410页

作者： LiangFANG FengXIAO ZushuLI ZainanTAO DepartmentofAppliedPhysics ChongQingUniversityChongqing400044China ChongQingInstituteofTechnology Chongqing400050China SatelliteVentureBusinessLaboratory KyushuInstituteofTechnologyKitakyushu804-8550Japan

The density of ni-AI alloys in both liquid state and solid-liquid coexistence state was measured with a modified pycnometric method. It was found that the density of ni-AI alloys decreases with increasing temperature and al concentration in the alloys. The molar volume of liquid ni-AI binary alloys increases with the increase of temperature and al concentration. The partial molar volume of al in ni-AI binary alloy was calculated approximately. The molar volume of liquid ni-AI alloy determined in the present work shows a negative deviation from the ideal linear molar volume.

关键词： ni-al alloy Density Modified pycnometric method Molar volume aluminum

Microscopic phase-field simulation of the coarsening behavior of coherent precipitates in ni-al alloys

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Journal of University of Science and Technology Beijing 2008年第2期15卷 161-166页

作者： Yanli Lu Zheng Chen Yongxin Wang Yongsheng Li School of Materials Science and Engineering Northwestern Polytechnical University Xi＇an 710072 China State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi＇an 710072 China

On the basis of the microscopic phase-field dynamic model and the microelasticity theory, the characteristics of the coarsening behavior of γ＇ phase in ni-al alloys have been systematically studied in a certain volume fraction of the precipitates. It was found that the initial irregular shape, randomly distributed γ＇ phase, gradually transformed into cuboidal shape, regularly aligned along the [100] and [010] directions, and a highly preferential selected microstructure was formed during the later stage of precipitation. The volume fraction of the precipitates produced some effects on the precipitate morphology but did not produce an obvious effect on the regularities of precipitate distribution. The coarsening rate constant from the cubic growth law decreased as a function of volume fraction for small volume fractions, remained constant for intermediate volume fractions, and increased as a function of volume fraction for large volume fractions. During the coherent coarsening process, four ＂splitting＂ patterns between γ＇ phases, which belonged to different antiphase domains, were produced via particle aggregation, such as an L-shaped pattern, a doublet, a triplet, and a quartet.

关键词： ni-al alloy precipitates elastic strain coarsening microscopic phase-field simulation

Microscopic phase-field simulation including elastic strain energy for early precipitation process of ni-al alloys with medium al content

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Progress in Natural Science:Materials International 2005年第12期15卷 1104-1109页

作者： LU Yanli,CHEN Zheng,LI Yongsheng,WANG Yongxin and CHU Zhong State Key Laboratory of Solidification Processing,School of Materials Science and Engineering,Northwestern Polytechnical University,Xi’an 710072,China State Key Laboratory of Solidification Processing School of Materials Science and Engineering Northwestern Polytechnical University Xi''an 710072 China

The early precipitation process of ni-al alloy was studied on the atomic scale based on the microscopic phase-field kinetic *** investigated the effect of elastic strain energy on precipitation mechanism and morphological evolution of the *** results show that at the early stage of precipitation,γ’ ordered phase presents non-directional and irregular shape during the process of aging,the γ’ ordered phases change into the quadrate shape and their orientations become more obvious; at the later stage,the γ’ precipitates present quadrate shape with round corner and align along the [100] and [010] *** mechanism of early precipitation for ni-13at.%A1 alloy is the mixed mechanism of non-classical nucleation growth and spinodal decomposition and near to non-classical nucle-ation growth,and the mechanism of early precipitation for ni-15.8at.% al alloy is the mixed mechanism of non-classical nucleation growth and spinodal decomposition and near to spinodal decomposition.

关键词： ni-al alloy early precipitation microscopic phase-field simulation elastic strain energy

Precipitate Behavior and Microstructure Evolution of γ′ phase in ni-al alloys with the Internal Elastic Strain

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Precipitate Behavior and Microstructure Evolution of γ′ ph...