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China Foundry 2025年

作者： Wen-tong Liu Yi-dong Wu Lei Gao Jing-yang Chen Cheng-bo Xiao Xi-dong Hui State key laboratory for advanced Metals and materials University of Science and Technology Beijing Science and Technology on advanced high temperature structural materials laboratory Beijing Institute of Aeronautical Materials

The size and shape effect(SSE) of components has become a critical issue for mechanical properties, application reliability, and processing. In this study, the creep rupture life(CRL) of components with different wall thicknesses and positions in a combustion chamber casing simulator made of K439B superalloy was investigated. The intrinsic mechanisms of the SSE were explored from the dendrite structure, volume fraction and size of the γ' phase, and element segregation, etc. It is shown that this casting exhibits a strong SSE of creep rupture life, characterized by a significant difference in the CRL values up to 60% with the variation of wall thickness and position in the casing. In terms of casting technology, the influence of SSE on CRL is actually determined by the cooling rate. The SSE on the creep rupture life originates from the dendrite structure(such as the secondary dendrite arm spacing), volume fraction size of the γ' phase in the dendrite trunk, and elements segregation rate. This work may have implications for the design and application of engineering components with large sizes and complex structures.

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Isothermal forging of γ-TiAl based alloys

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中国有色金属学会会刊：英文版 2003年第6期13卷 1325-1328页

作者：黄朝晖 national defense key laboratory of advanced high temperature structural materials

The true stress—strain curves and processing window of Ti-47Al-2Cr-1Nb were set up through thermal physical simulation. A method for refinement of the as-cast+HIPped structure was submitted, which included two-step deformation with a short intermediate heat-treatment between double deformations. The break-down operation of the canned ingot was performed by the isothermal forging processing mentioned above. The refining mechanism is characterized as breaking and bending of the as-cast+HIPped lamellae, dynamic recrystallization, and static globularization. Thus, a uniform and refined billet microstructure is obtained for the final component by forging operation. The deformation of a model disc is accomplished by the subsequent single-step isothermal forging at 1 100(1 150 ℃) using a closed compression die.

关键词： γ-TiAi合金等温锻造显微结构钛合金

Dual-ligand chiral MOFs exhibiting circularly polarized room temperature phosphorescence for anti-counterfeiting

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Science China Chemistry 2025年

作者： Hongrui Zheng Qingqing Wang Xinchao Wang Fei Wang Shangda Li Jian Zhang State key laboratory of structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences Fujian key laboratory of Polymer materials College of Chemistry and Materials Science Fujian Normal University

advanced chiral optical materials exhibiting circularly polarized room-temperature phosphorescence（CPRTP） possess significant research value. This study facilitates the synthesis of chiral metal-organic frameworks（CMOFs） with good CPRTP performance by implementing a dual-ligand strategy. By self-assembling the luminescent ligand H2BIIM with the chiral ligands L-or D-H2IDPA in the presence of Zn（II） ions, two robust three-dimensional（3D） CMOFs were successfully constructed. These complexes demonstrated intense fluorescence and exhibited prolonged yellow room-temperature phosphorescence（RTP） with a duration of up to 6 s. Notably, they exhibited both circularly polarized fluorescence(glum= ±7.57 × 10-3) and CPRTP(glum=±2.68 × 10-3). These unique properties were effectively utilized in the creation of multi-color anti-counterfeiting patterns,underscoring their promising potential for a wide range of applications.

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Role of iron ore in enhancing gasification of iron coke:structural evolution,influence mechanism and kinetic analysis

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International Journal of Minerals,Metallurgy and materials 2025年第1期32卷 58-69页

作者： Jie Wang Wei Wang Xuheng Chen Junfang Bao Qiuyue Hao Heng Zheng Runsheng Xu School of Chemistry and materials Science Hubei Engineering UniversityXiaogan 432000China key laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081China Institue of Ironmaking Technology Baosteel Central Research InstituteShanghai 201999China State key laboratory of advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

The utilization of iron coke provides a green pathway for low-carbon *** uncover the influence mechanism of iron ore on the behavior and kinetics of iron coke gasification,the effect of iron ore on the microstructure of iron coke was ***,a comparative study of the gasification reactions between iron coke and coke was conducted through non-isothermal thermogravimetric *** findings indicate that compared to coke,iron coke exhibits an augmentation in micropores and specific surface area,and the micropores further extend and *** provides more adsorption sites for CO_(2) molecules during the gasification process,resulting in a reduction in the initial gasification temperature of iron *** the heating rate in non-isothermal gasification can enhance the reactivity of iron *** metallic iron reduced from iron ore is embedded in the carbon matrix,reducing the orderliness of the carbon structure,which is primarily responsible for the heightened reactivity of the carbon *** kinetic study indicates that the random pore model can effectively represent the gasification process of iron coke due to its rich pore ***,as the proportion of iron ore increases,the activation energy for the carbon gasification gradually decreases,from 246.2 kJ/mol for coke to 192.5 kJ/mol for iron coke 15wt%.

关键词： low-carbon ironmaking iron coke gasification structural evolution kinetic model

Characterization of creep behavior of TiAl alloy with high Nb content at elevated temperatures

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Rare Metals 2016年第1期35卷 106-112页

作者： Cheng-Li Dong Hui-Chen Yu Ze-Hui Jiao Beijing key laboratory of Aeronautical materials Testing and Evaluation Science and Technology on Advanced High Temperature Structural Materials LaboratoryBeijing Institute of Aeronautical Materials Science and Technology on advanced high temperature structural materials laboratory Beijing Institute of Aeronautical Materials

Creep experiments of the TiAl alloy with high Nb content were conducted to consider both the temperature dependence and stress dependence of its creep *** creep curves were characterized by Theta constitutive model,and Newton-Gauss method was applied to obtain the material *** on the rupture strain,the rupture life of the TiAl alloy was able to be predicted by Theta constitutive *** results show that the creep curves of the TiAl alloy contain primary creep,secondary creep and tertiary creep stages,especially for the lower *** rupture life of the TiAl alloy decreases with the increase in either applied stress or *** constitutive model is able to describe the creep deformation of the TiAl alloy accurately,and the predicted life agrees well with the experimental result.

关键词： TiAl alloy Creep Rupture Life prediction Theta constitutive model

Oxidation behavior of Ni（Co）CrAlYHf（Si） coatings on DS superalloy at 1150℃

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中国有色金属学会会刊：英文版 2006年第A2期16卷 166-170页

作者：黄朝晖谭永宁赵希宏李建平张强 national Defence key laboratory for advanced high temperature structural materials Beijing Institute of Aeronautical Materials Beijing 100095 China

Two Ni(Co)CrAlY coatings were deposited by EB-PVD method on a DS superalloy of Ni-Al-Cr-Co-W-Mo-Ta-Hf system. SEM, XEDS and XRD were used to study the oxidation behavior of the coatings. The two coatings show a good protection for the DS superalloy. The results of the isothermal oxidation test at 1150°C for 100 h show that the oxidation tendency obeys the parabolic law, and the oxidation rate constant Kp of the coated specimens decreases to about 1/3 of that for the bare superalloy. After oxidation, a continuous alumina-based scale is formed at the surfaces of the coated samples. Y2O3, NiO and SiO2 are also detectable in the oxide scale. A large number of Al in the coating is consumed due to high-temperature diffusion and oxidation reactions, and the NiAl phases in the coating are almost completely transformed to Ni3Al phases. For the Hf-bearing coating, some HfO2 particles exist at the interface between the coating and the substrate. Although internal oxidation occurs, the coating still shows a good adhesion with the superalloy substrate even after oxidation for 100 h. For the bare DS superalloy, after 100 h oxidation at 1150°C, only discontinuous alumina-based oxide particles exist on the surface. Oxide spallation occurs for the bare alloy.

关键词： DS高温合金 Ni(Co)CrAlY镀层氧化行为相互扩散 EB-PVD

Effects of Dendritic Orientation on Stress Rupture Properties of DD6 Single Crystal Superalloy

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Journal of Iron and Steel Research International 2011年第10期18卷 66-71页

作者： SHI Zhen-xue LI Jia-rong LIU Shi-zhong ZHAOJin-qian national key laboratory of Science and Technology on advanced high temperature structural materials Beijing Institute of Aeronautical Materials Beijing 100095 China

DD6 single crystal superalloy slabs were prepared with seed method in the direetionally solidified furnace with high temperature gradient. The transverse stress rupture properties and fracture hehaviour of the alloy at 760 ℃/758 MPa, 850 ℃/550 MPa and 980 ℃/250 MPa were investigated and compared with those of longitudinal specimens. The transverse stress rupture lives are corresponding with the longitudinal stress rupture lives at 760 ℃/758 MPa and 850 ℃/550 MPa. The transverse stress rupture lives are slightly less than the longitudinal stress rupture lives at 980 ℃/ 250 MPa. The fracture mechanism of the transverse stress rupture of the alloy at 760 ℃/758 MPa shows quasi-cleav- age mode and the fracture mechanism at 980 ℃/250 MPa shows dimple mode, while the fracture mechanism at 850 ℃/ 550 MPa shows quasi-cleavage and dimple mixture mode. At higher temperature and lower stress, the microeracks are easier to initiate and interconnect in the transverse specimen than those in longitudinal specimen because there are interdendritic regions perpendicular to the axis of stress.

关键词： DD6 single crystal superalloy stress rupture property fracture behaviour

Effect of Hf on Stress Rupture Properties of DD6 Single Crystal Superalloy After Long Term Aging

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Journal of Iron and Steel Research International 2012年第7期19卷 66-70页

作者： SHI Zhen-xue LI Jia-rong LIU Shi-zhong national key laboratory of Science and Technology on advanced high temperature structural materials Beijing Institute of Aeronautical Materials Beijing 100095China

The specimens of the second generation single crystal superalloy DD6 with different Hf contents were prepared in the directionally solidified furnace with a high temperature gradient. The long term aging of the specimens after full heat treatment was performed at 1040℃for 800 h. The effect of Hf on the microstructure and stress rupture properties under 980℃/250 MPa of the alloy after long term aging was investigated. The results show that the γ＇ coarsening and rafting and no topologically close packed phase （TCP） are observed in the microstructures of DD6 alloy with different Hf contents after aged at 1 040℃ for 800 h. It indicates that DD6 alloy with different Hf contents all possesses good microstructure stability. With increasing Hf content the rupture life after long term aging turns shorter and the elongation represents the increasing first and decreasing afterwards. The fracture mechanism of the alloy with different Hf contents at 980℃/250 MPa all shows dimple model. The influence of the microstructures on the stress rupture properties of the alloy is also discussed.

关键词： DD6 single crystal superalloy stress rupture property long term aging

Influence of γ' precipitate on deformation and fracture during creep in PM nickel-based superalloy

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Progress in Natural Science:materials International 2021年第2期31卷 303-309页

作者： Zichao Peng Jinwen Zou Jie Yang Gaofeng Tian Xuqing Wang Science and Technology on advanced high temperature structural materials laboratory Beijing Institute of Aeronautical MaterialsAECC

FGH96 is a powder metallurgy nickel based superally used for turbine disk of aero-engines. In the present study FGH96 alloy with four different γ' precipitate microstructures were produced via solution heat-treatment with different cooling rates, and the maximum cooling rate reached 400°C/min which was a super cooling rate for Nickel-based superalloy. The creep tests were conducted for PM FGH96 alloy under the testing condition of 704°C and 690 MPa. The relationship between the creep properties and the distribution of γ' precipitate was established. The creep mechanism was analyzed by using TEM and ACTEM, and the dislocation movement was studied at the atomic scale. The creep strain rate was calculated through a physically based crystal slip model established based on crystal plasticity. The calculated results were consistent with the test ones, illustrating the validity of the model. The fracture mechanism was also investigated, and the results showed that the creep cracks generated on the surface due to the oxidation. It was observed that the cracks propagated in different ways depending on the different average diameters of γ' precipitate. With the decrease of the average γ' precipitate size,the critical shearing stress increased and the resistance of the dislocation slipping increased. The fracture mechanism for the primary stage transformed from intragranular to intergranular due to the change of dislocation slipping.

关键词： PM FGH96 superalloy Microtwinning γ′ precipitate Fracture mechanism Physically-based creep model

Application of inverse method to estimation of boundary conditions during investment casting simulation

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Acta Metallurgica Sinica(English Letters) 2009年第6期22卷 429-434页

作者： Haipeng JIN Jiarong LI Dong PAN national key laboratory of advanced high temperature structural materials Institute of AeronauticalMaterials Beijing 100095 China key Lab for advanced materials Processing Technology MOE Department of Mechanical EngineeringTsinghua University Beijing 100084 China

Inverse method was used in single crystal superalloy DD6 processing simulation during solidification. Numerical modeling coupled with experiments has been used to estimate the interface heat transfer coefficient （IHTC） between the surface of slab casting and inner mold. Calculated temperature dependent values of IHTC were obtained from a numerical solution. The calculated temperatures agreed well with the measurement of cooling profile.

关键词： Numerical simulation Single crystal Inverse method Boundary conditions