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Effect of Al on Microstructure and Mechanical Properties of ATI 718Plus by Laser Additive Manufacturing

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Acta Metallurgica Sinica(English Letters) 2024年第11期37卷 1891-1906页

作者： Zhipeng Zhang Jide Liu xinguang wang Zhaokuang Chu Yizhou Zhou Jianjun wang Jinguo Li Key Laboratory for Anisotropy and Texture of Materials(MOE) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China Research Center for Metallic Wires Northeastern UniversityShenyang110819China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

To clarify the mechanism of the role of Al element in the additive manufacturing of Ni-based superalloys,ATI 718Plus alloys with varying Al contents(1,3,and 5 wt%)were fabricated using the laser additive manufacturing and the effects of Al content on the microstructure and mechanical properties were systematically *** experimental and CALPHAD simulation results show that with the increase in Al addition,the freezing range of the alloys was lowered,but this has a paradoxical effect on the susceptibility of the alloy to hot-tearing and solid-state *** addition of Al increased theγ′and Laves phase volume fractions and suppressed the precipitation of theη*** improvingγ/γ′lattice misfits effectively promoted the transformation ofγ′phase from spherical to *** precipitation of NiAl phase in the 5 wt%Al-added alloy was determined,the formation mechanism of NiAl phase was analyzed,and the solidification sequence of the precipitated phase in the alloy was *** addition,with the increase in Al addition,the microhardness of the alloy increased gradually,the tensile strength increased at first and then decreased,but the plasticity deteriorated *** insights gained from this study offer valuable theoretical guidance for the strategic compositional design of additively manufactured Ni-based superalloys destined for deployment under extreme conditions.

关键词： Laser additive manufacturing ATI 718Plus Laves phase Microstructure Mechanical properties

Effect of solution cooling rate on the microstructure and creep deformation mechanism of a rhenium-free second-generation single crystal superalloy

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Journal of Materials Science & Technology 2022年第36期131卷 14-29页

作者： Xipeng Tao Yunling Du xinguang wang Jie Meng Yizhou Zhou Jinguo Li Xiaofeng Sun Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

Various cooling scenarios(water,oil,air and furnace)were employed to study the impacts of the solution cooling rate(SCR)on the microstructure and creep behavior of a novel single-crystal(SX)*** results showed that the cubic degree and size of theγphases were inversely proportional to the *** creep life first increased and then dropped dramatically with a reduction in the *** creep life of the sample cooled with air cooling(AC)was the highest,up to 144.90 h at 800℃/750 MPa and160.15 h at 1100℃/137 *** creep at 800℃/750 MPa,the improved creep life of the AC sample was mainly attributed to the fine cubicγphases,which decreased the rate ofγ-phase coarsening and favoured plastic deformation by promoting the active movement of *** AC helped theγphases become rich in Al,Ti and Ta while depleted in Co and Cr,which enhanced its stacking fault energy,thus promoting the formation of dislocation ***,the largest negative lattice misfit caused by AC induced denserγ/γinterface dislocation networks at 1100℃/137 MPa,which efficiently reduced the minimum creep *** calculated average dislocation spacing results indicated that the smallest density of excess dislocations corresponded to the AC sample,proving its greatest creep ***,the size of the secondaryγphases first decreased and then increased sharply with decreasing SCR during creep at 1100℃/137 MPa,when fine secondaryγphases had a positive role in the blockage of dislocation movement in the ***,the comprehensive SCR effect was explored to provide more guidance in the design of Re-free SX superalloys.

关键词： Solution cooling rate Microstructure Creep property Deformation mechanism Single crystal superalloy

The interaction and migration of deformation twin in an eutectic high-entropy alloy AlCoCrFeNi2.1

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Journal of Materials Science & Technology 2019年第5期35卷 902-906页

作者： Yaoli Zhang Jinguo Li xinguang wang Yiping Lu Yizhou Zhou Xiaofeng Sun Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China School of Materials Science and Engineering University of Science and Technology of China Hefei 230026 China Key Laboratory of Space Manufacturing Technology Chinese Academy of Sciences Beijing 100094 China School of Materials Science and Engineering Dalian University of Technology Dalian 116024 China

An eutectic high-entropy alloy consisting Al, Co, Cr, Fe and Ni elements was prepared by vacuum directional solidification technology. The alloy exhibits excellent comprehensive mechanical performance during tension at temperature range of 600–700℃. The microstructure reveals the intersection of twintwin is the prevailing deformation mechanism and the twins play a dual role in strengthening and toughening the alloy in the thermomechanical process. The deformation twin variants I and were formed by the edge dislocation 112 and the mixed dislocation 211 on the {111} crystal planes, respectively. Besides, the dislocation jogs and kinks caused by twin intersection on the slip planes can strengthen the alloy, which may contribute to the high strength(the tensile strengths at the 600°and 700°tensile tests are respectively780 MPa and 630 MPa.). Moreover, the coherent twin boundary migration has the function of coordinating deformation and contributes to the high ductility of the alloy.

关键词： Eutectic high-entropy alloy Tensile properties Deformation twin Dislocation jog Twin migration

Hot Deformation Behavior and Workability of a New Ni–W–Cr Superalloy for Molten Salt Reactors

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Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1453-1466页

作者： Long Liu Zijian Zhou Jie Yu xinguang wang Chuanyong Cui Rui Zhang Yizhou Zhou Xiaofeng Sun Shi‑Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Fushun Special Steel Co. LtdFushun 113000China

The hot deformation behavior of a newly developed Ni–W–Cr superalloy for use in 800℃molten salt reactors(MSRs)was looked into by isothermal compression tests in the temperature range of 1050–1200℃with a strain rate of 0.001–1 s^(−1)under a true strain of *** Arrhenius-type model for the Ni–W–Cr superalloy was constructed by fitting the corrected flow stress *** this model,the effect of dispersion of solid solution elements during thermal deformation on microstructure evolution was considered,as well as the effects of friction and adiabatic heating on the temperature and strain rate-dependent variation of flow *** hot deformation activation energy of the Ni–W–Cr superalloy was 323 kJ/mol,which was less than that of the Hastelloy N alloy(currently used in MSRs).According to the rectified flow stress data,processing maps were *** conjunction with the corresponding deformation microstructures,the flow instability domains of the Ni–W–Cr superalloy were determined to be 1050–1160℃/0.03–1 s^(−1)and 1170–1200℃/0.001–0.09 s^(−1).In these deformation conditions,a locally inhomogeneous microstructure was caused by flow-i.e.,incomplete dynamic recrystallization and hot working parameters should avoid sliding into these *** ideal processing hot deformation domain for the Ni–W–Cr superalloy was determined to be 1170–1200℃/0.6–1 s^(−1).

关键词： Ni-W-Cr Superalloy Hot deformation behavior Constitutive equation Processing map Microstructure evolution

Influence of Ta/Al ratio on the microstructure and creep property of a Ru-containing Ni-based single-crystal superalloy

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Journal of Materials Science & Technology 2021年第30期89卷 16-23页

作者： Wei Song xinguang wang Jinguo Li Jie Meng Yanhong Yang Jinlai Liu Jide Liu Yizhou Zhou Xiaofeng Sun Shi-changxu Innovation Center for Advanced Materials Superalloys DivisionInstitute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

Two alloys with different Ta and Al contents were applied to study the influence of Ta/Al ratio on the microstructural evolution and creep deformation under high *** increase of Ta/Al ratio made theγ/γ'lattice misfit more negative and enhanced the volume fraction ofγ'phase,which produced cubic and smallγ'phase in the initial *** initial tinyγ'phases impeded the dislocations movement and delayed the course of complete raftedγ'phase during the origination of creep deformation,which prolonged the time of the primary creep ***,the increase of Ta/Al ratio and addition of Ru produced the denser and stable dislocation networks,the high APB energy and better solution strengthening,which hindered the climbing and sliding of dislocations,and restrained the formation of superdislocations in theγ'*** second creep stage was extended,and the minimum creep rate was ***,the increase of whole creep life of the alloy containing high Ta/Al ratio was attributed to the prolongation of the primary and second creep stages,and the low minimum creep *** appearance of the topological inversion phenomenon during the tertiary creep stage was the primary cause for the sudden increase of the creep strain rate of the alloy containing low Ta/Al ***,the high creep strain rate of the alloy containing high Ta/Al ratio during the tertiary creep stage was related to the occurrence and extending of the cracks near the *** alloys would lose efficacy within 20 h-30 h.

关键词： Ni-based superalloys Ta/Al ratio High temperature creep Interfacial dislocation networks γ'rafting

Effect of Ta on Tensile Behavior and Deformation Mechanism of a Nickel-Based Single Crystal Superalloy

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Acta Metallurgica Sinica(English Letters) 2024年第11期37卷 1921-1934页

作者： Mingtao Ge xinguang wang Yongmei Li Zihao Tan Xipeng Tao Yanhong Yang Liang wang Chunhua Zhang Song Zhang Yizhou Zhou Xiaofeng Sun Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering Shenyang University of TechnologyShenyang110870China

The effects of Ta on the tensile behavior and deformation mechanisms of a Ni-based single crystal superalloy were investigated in this study from room temperature to elevated *** findings demonstrated that the higher content of Ta could improve the tensile properties of the alloy at different *** to the different deformation mechanisms at various temperatures,the influence of Ta on tensile deformation *** room temperature,the higher content of Ta enhanced the solid solution strengthening,which would enhance the tensile strength of 6.5Ta *** standard heat treatment of 6.5Ta alloy,precipitation of the secondaryγʹphase would hinder the movement of *** the temperature was elevated to 760℃,the higher content of Ta not only promoted the interaction of stacking faults to form Lomer-Cottrell(L-C)locks that impeded dislocation motion,but also reduced the occurrence of dislocation pile-up groups,thus enhancing the yield *** 1120℃,due to the narrowerγchannels and higher APB energy inγʹphase of the alloy with higher Ta addition,the processes of bypassing and shearing of dislocations were hindered,***,the denser and more regular dislocation networks were formed in 6.5Ta alloy;and thus,the tensile strength of 6.5Ta alloy was *** study systematically investigated the effect of Ta on the tensile behavior at three different temperatures,which provided an important theoretical basis for the design of nickel-based single crystal superalloys in the future.

关键词： Ta Single crystal superalloy Tensile behavior Stacking fault Deformation mechanism

Effect of thermal exposure on the microstructure and creep properties of a fourth-generation Ni-based single crystal superalloy

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Journal of Materials Science & Technology 2021年第10期69卷 180-187页

作者： Yeshun Huang xinguang wang Chuanyong Cui Zihao Tan Jinguo Li Yanhong Yang Jinlai Liu Yizhou Zhou Xiaofeng Sun Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

The effect of thermal exposure on microstructure and creep properties of a fourth-generation nickelbased single crystal superalloy was *** thermal exposure of samples after the full heat treatment was carried out at 1000℃,1100℃ and 1140℃ for 100 h and 200 *** γ’ coarsening,γ’ rafting and γ channel widening were observed in samples after thermal *** the thermal exposure time was constant,the morphology of γ’ phase in the alloy evolved significantly with increasing aging *** interracial dislocation networks in aged samples after creep ruptured gradually became irregular and sparse with the increase of exposure *** the higher exposure temperature was used,enla rgement of the defect pores was observed in samples,the microcracks were more likely to initiate and propagate at the corner of these *** aging at 1000℃ for 100 h,the creep life at 1140℃/137 MPa was slightly longer than that of heat-treated sample,which could be attributed to the slightly coarsened γ’ phase,homogenization of refractor *** contrast,the creep life of sample exposed at 1140℃ for 100 h was greatly *** decrease of creep life was dominated by the rafting of γ’phase,the irregular interfacial dislocation networks as well as the enlargement of homogenization pores.

关键词： Ni-based single crystal superalloys Thermal exposure Microstructural evolution Creep properties Porosity

On the γ' precipitates of the normal and inverse Portevin-Le Chatelier effect in a wrought Ni-base superalloy

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Journal of Materials Science & Technology 2019年第1期35卷 84-87页

作者： xinguang wang Guoming Han Chuanyong Cui Shuai Guan Jinguo Li Guichen Hou Yizhou Zhou Xiaofeng Sun Institute of Metal Research Chinese Academy of Sciences

The Portevin-Le Chatelier(PLC) effects in a wrought Ni-base superalloy with different γ' precipitates contents have been investigated. Detailed analysis on the serration type of the tensile curves indicates that the γ' precipitates have a decisive influence on the transformation from normal to inverse PLC behavior, which is rarely proposed in other works. It is considered that the γ' precipitates play the same role in PLC effect as temperature and strain rate for the investigated wrought Ni-base superalloy.

关键词： Normal and inverse PLC effec γ’ precipitates Dynamic strain aging Critical strain Wrought Ni-base superalloy

National guidelines for diagnosis and treatment of breast cancer 2022 in China(English version)

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Chinese Journal of Cancer Research 2022年第3期34卷 151-175页

作者：无 xinguang wang Xue Chen Dongfeng Niu Yang Yang Jingyi Zhao National Health Commission of the People’s Republic of China Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education Beijing) Peking University Cancer Hospital&Institute

Contents 1. Breast cancer screening 1.1 Recommendations for females at normal risk 1.1.1 Age 20-39 years old 1.1.2 Age 40-69 years old 1.1.3 Age≥70 years old 1.2 Recommendations for females at increased risk 2. Diagnosis of breast cancer 2.1 Clinical manifestations 2.1.1 Breast lump 2.1.2 Nipple discharge 2.1.3 Skin changes 2.1.4 Abnormalities in nipple and areola 2.1.5 Enlarged axillary lymph nodes。

关键词： diagnosis breast cancer