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Advances in laser powder bed fusion of ceramic-reinforced superalloys:Processing,microstructure,properties,and perspectives 认领 引用 被引量：1
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作者 Peixin Yang Haijun Su +7 位作者 Yinuo Guo Zhonglin Shen Xin Hao Quandong Hu Yihe Zhang Min Guo Min Yang Wenchao Yang 《Metals Advances》 SCIE EI CAS CSCD 2026年第4期1-22,共22页
Superalloys are extensively utilized in the aerospace and energy industries due to their outstanding high-temperature strength,thermal stability,and corrosion resistance.However,the rapidly growing demands for higher ... Superalloys are extensively utilized in the aerospace and energy industries due to their outstanding high-temperature strength,thermal stability,and corrosion resistance.However,the rapidly growing demands for higher thrust-to-weight ratios and elevated turbine inlet temperatures in advanced engines have posed significant challenges to current hot-section component materials.Ceramics,with their inherent high hardness and melting points,are promising reinforcement candidates.Incorporating ceramics into superalloys enables the design of composites that overcomes the intrinsic limitations of conventional alloys.The newly-developed laser powder bed fusion(LPBF)technique provides great potential for fabricating such composites with tailored structures and properties.However,porosity and cracking frequently arise during LPBF due to complex multi-field interactions,thus degrading their service performance.This review systematically summarized advances in LPBF-fabricated ceramic-reinforced superalloys.The key coupling relationships between ceramic particle characteristics,LPBF process parameters,and high-temperature service performance are systematicallyclarified.The metallurgical process,microstructure evolution,and precipitation behavior of superalloy composites are comprehensively scrutinized.The initiation and propagation mechanisms of metallurgical defects in these composites are explicitly analyzed and elucidated.Furthermore,the mechanical properties of the composite materials and their underlying strengthening mechanisms are thoroughly addressed.Finally,the bottleneck problems associated with ceramic-reinforced superalloy composites fabricated by LPBF are synthesized,and future perspectives are proposed. 展开更多
关键词 Laser powder bed fusion Ceramics Superalloy Metallurgical defect Strengthening mechanisms
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Quantitative phase-field simulation of precipitation kinetics ofγ′phase in multicomponent Co-based superalloys 认领 引用
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作者 Jia Chen Min Guo +7 位作者 Tingting Cui Xingbing Zhang Fusheng Tan Min Yang Wenchao Yang Taiwen Huang Haijun Su Lin Liu 《Metals Advances》 SCIE EI CAS CSCD 2026年第7期52-66,共15页
Co-Al-W-based alloys have been recognized as promising next-generation structural materials for high-temperature applications due to the formation of theγ′strengthened phase.However,optimizing these superalloys thro... Co-Al-W-based alloys have been recognized as promising next-generation structural materials for high-temperature applications due to the formation of theγ′strengthened phase.However,optimizing these superalloys through experimental studies is a significant challenge because of complex element interactions.This paper investigates the temporal processing and mechanisms ofγ′precipitates in novel Co-based superalloys using the phase-field method.By coupling the calculation of phase diagrams(CALPHAD)approach for the phase free energy and chemical mobility involving element interactions,and by calculating thermophysical parameters of alloys using first-principles,we developed a quantitative phase-field model for multicomponent systems.Using this model,the element diffusion path andγ′evolution path are simulated in ternary diffusion couples and aging alloys,and the results align well with experimental observations.Furthermore,the effects of W content in Co-Al-W alloys on the coarsening kinetics and mechanisms ofγ′precipitates during long-term aging are systematically studied.It is found that increasing W content results in higherγ′volume fraction and increasedγ′coarsening rate.The accelerated coarsening is primarily attributed to the shortened inter-particle spacing betweenγ′precipitates,which is comprehensively analyzed through element diffusion distance and flux.Additionally,the model is extended to quaternary systems and successfully applied to Co-Ni-Al-W alloy.This study provides a novel method for the quantitative prediction ofγ/γ′microstructures and contributes to the alloy design and processing optimization of novel superalloys. 展开更多
关键词 Co-based superalloys γ′precipitate Phase-field model Calculation of phase diagrams method Multicomponent alloy
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Biodiversity of Amphibians Along the Elevational Gradient of Mount Leigong: Checklist, Distribution, and Conservation 认领 引用
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作者 Tuo SHEN Chaobo FENG +5 位作者 Xiujun TANG Caichun PENG Jing LIU Xue GOU Lang MU Haijun SU 《Asian Herpetological Research》 SCIE CAS CSCD 2026年第1期62-66,共5页
Dear Editor,Mountain systems have long been refuges for many species,often viewed as"islands"that promote speciation due to geographic isolation(Rahbek et al.,2019).Their high environmental heterogeneity fos... Dear Editor,Mountain systems have long been refuges for many species,often viewed as"islands"that promote speciation due to geographic isolation(Rahbek et al.,2019).Their high environmental heterogeneity fosters centers of endemism,and they harbor over 85%of global species diversity(Zhao et al.,2022).Consequently,mountains are key systems for exploring biodiversity patterns along elevational gradients,where species richness often follows four recognized models:monotonic decrease,unimodal pattern(forward and backward peak patterns),and low plateau followed by a decrease along the elevational gradient(McCain et al.,2010). 展开更多
关键词 species richness conservation biodiversity elevational gradient amphibians biodiversity patterns Mount Leigong checklist
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Foraging habitat selection of overwintering Black-necked Cranes in the farming area surrounding the Caohai Wetland, Guizhou Province, China 认领 引用 被引量：12
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作者 Dawei Wu Canshi Hu +2 位作者 Mingming Zhang Zhumei Li Haijun Su 《Avian Research》 SCIE CSCD 2020年第1期74-82,共9页
Background: Understanding how overwintering birds choose foraging habitats is very important for conservation management. The overwintering Black-necked Crane(Grus nigricollis) feeds on crop remains in farmlands;thus,... Background: Understanding how overwintering birds choose foraging habitats is very important for conservation management. The overwintering Black-necked Crane(Grus nigricollis) feeds on crop remains in farmlands;thus, reasonable conservation management of this type of farmland that surrounds wetlands is critical for the overwintering populations of the Black-necked Crane;however, it is not clear how the Black-necked Crane chooses the foraging land in the farmland.Methods: A thorough field positioning survey of all foraging sites in farmland areas around the Caohai Wetland and a-sampling analysis of habitat selection by the Black-necked Crane were conducted during the winters from 20162017 and 2017-2018.Results: Multiple factors contributed to the selection of foraging habitat in farmlands, i.e., food factors(crop remains and tillage methods) > human disturbance factors(distance to road and settlement) > topography factors(slope aspect), listed according to the strength of influence. Additionally, Black-necked Cranes tend to choose farmland sites where there was no machine tillage, the crop remains were > 500 g/m^2, the distance to residences ranged from 100 to 500 m, the distance to roads ranged from 50 to 100 m, and the slopes exhibited western or eastern aspects. As the winters progressed, the volume of the edible crop remains declined, and the influences of the other main factors also changed, i.e., the factors of human disturbance(distance to road and settlement) became less important, while the effect of the food factor(crop remains) was strengthened. Thus, the foraging sites near the road became more important.Conclusion: The farming area surrounding the Caohai Wetland is very important for the overwintering Black-necked Crane. Food factors and human disturbance factors are the main factors that influence the choice of feeding ground. 展开更多
关键词 Black-necked Crane Caohai wetland in Guizhou Farmland around the wetland Foraging habitat selection Overwintering period
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Coupling phase field with creep damage to study γ’evolution and creep deformation of single crystal superalloys 认领 引用 被引量：5
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作者 Min Yang Jun Zhang +5 位作者 Weimin Gui Songsong Hu Zhuoran Li Min Guo Haijun Su Lin Liu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第12期129-137,共9页
A phase-field model coupling with elastoplastic de fo rmation and creep damage has been built to study the micro structural evolution and deformation behavior for Ni-Al single crystal alloy during the whole creep proc... A phase-field model coupling with elastoplastic de fo rmation and creep damage has been built to study the micro structural evolution and deformation behavior for Ni-Al single crystal alloy during the whole creep processing.The relevant experiments were conducted to verify the model validity.The simulation re sults show that under the tensile creep at 1223 K/100 MPa,cubic γ’phases coarsen along the direction parallel to the axis of tensile stress during the first two creep stages;and spindle-shaped and wavy γ’phases are fo rmed during tertiary creep,similar to the experimental results.The evolution mechanism of γ’phases is analyzed from the perspective of changes of stress and strain fields.The"is land-like"γ phase is observed and its formation mechanism is discussed.With the increase of creep stress,the directional coarsening of γ’phase is accelerated,the steady-state creep rate is increased and the creep life is decreased.The comparison between simulated and experimental creep curves shows that this phase-field model can effectively simulate the performance changes during the first two creep stages and predict the influence of creep stresses on creep properties.Our work provides a potential approach to synchronously simulate the creep microstructure and property of superalloys strengthened by γ’precipitates. 展开更多
关键词 Phase-field model Single crystal superalloy γ’phase Creep behavior Creep damage
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Microstructure evolution and solidification behaviour of ZrB2-SiC composite ceramics fabricated by laser surface zone-melting 认领 引用 被引量：3
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作者 Zhuo Zhang Xiping Song +8 位作者 Haijun Su Hao Jiang Di Zhao Xiang Li Dong Dong Yuan Liu Zhonglin Shen Yinuo Guo Peixin Yang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第23期145-154,共10页
Microstructure evolution and solidification behaviour of ZrB2-SiC composite ceramics fabricated by laser surface zone-melting were investigated.Microstructure coarsening at high scanning speed and mi-crostructure r... Microstructure evolution and solidification behaviour of ZrB2-SiC composite ceramics fabricated by laser surface zone-melting were investigated.Microstructure coarsening at high scanning speed and mi-crostructure refining after turning off the laser was observed due to the changes in the solidification rate.The solidification behaviour from bottom to top of the molten pool was studied,where there are some coarsen eutectic bands caused by the secondary heating of the melting pool on the solidified eu-tectic zone in the molten pool.The deviation of melt composition from the eutectic ratio due to the volatilization of SiC can form a coarse primary ZrB2 phase among fine eutectic structure(single-phase instability),and the constitutional supercooling due to the accumulation of impurity elements can form coarse eutectic dendrites among fine eutectic structure(two-phase instability).Both single-phase insta-bility and two-phase instability are adverse to the mechanical properties,which should be prevented by adjusting the composition of raw materials and the solidification process. 展开更多
关键词 ZrB2-SiC Eutectic composite ceramics Microstructure evolution Solidification behaviour Laser surface zone-melting
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Formation and Evolution of Surface Morphology in Overhang Structure of IN718 Superalloy Fabricated by Laser Powder Bed Fusion 认领 引用 被引量：2
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作者 Haotian Zhou Haijun Su +6 位作者 Yinuo Guo Yuan Liu Di Zhao Peixin Yang Zhonglin Shen Le Xia Min Guo 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2023年第9期1433-1453,共21页
Controlling the overhang surface quality is still a formidable challenge in manufacturing the components with complex structures during laser powder bed fusion(LPBF).This study systematically uncovers the effects of t... Controlling the overhang surface quality is still a formidable challenge in manufacturing the components with complex structures during laser powder bed fusion(LPBF).This study systematically uncovers the effects of the volume energy density(VED)and overhang angle on the evolution of surface morphology and corresponding surface roughness(Ra)of top and down-skin surfaces of IN718 superalloy samples.The results show that balling,Plateau-Rayleigh instability,open pore and humping caused by the material stacking are the main factors contributing to the apparent deterioration of top surface quality.When the VED is 80–100 J/mm3,the high down-skin surface roughness is attributed to the serious dross caused by recoil pressure and sinking of the melt pool.Using insufficient VED(15–50 J/mm3)can easily lead to poor metallurgical bonding and material spalling on the down-skin surface.In addition,overhang angle also significantly affects down-skin surface roughness due to the stair effect and the adhered unmelted powders.An improvement in the surface quality of down-skin surface is observed when the overhang angle increases.Based on the finding of this investigation,an optical VED(59.5 J/mm3)significantly improves the top and down-skin surface quality and porosity of overhang samples.This study provides an insight into synergy ascension of the top and down-skin surface quality in the overhang structure. 展开更多
关键词 Laser powder bed fusion IN718 superalloy Surface roughness Overhang structure
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Species Diversity and Elevational Patterns of Reptiles in the Leigongshan National Nature Reserve, Guizhou Province, China 认领 引用
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作者 Xue GOU Caichun PENG +7 位作者 Tuo SHEN Chaobo FENG Lang MU Jing LIU Haijun SU Xiujun TANG Shize LI Xingui LI 《Asian Herpetological Research》 SCIE CAS CSCD 2026年第1期31-33,共3页
Dear Editor,Understanding patterns of species diversity is a primary research focus in macroecology,with its distribution patterns having been described and theoretically validated on a global scale(Peters et al.,2016... Dear Editor,Understanding patterns of species diversity is a primary research focus in macroecology,with its distribution patterns having been described and theoretically validated on a global scale(Peters et al.,2016;Sonne et al.,2025).Numerous studies have found that species richness of different taxa tends to decrease with increasing elevation and is modulated by latitudinal gradients(Peters et al.,2016;Dolson et al.,2024).This principle provides a crucial scientific basis for regional conservation planning.However,it still exhibits significant variations across different mountain ranges and taxa. 展开更多
关键词 patterns species diversity Leigongshan National Nature Reserve species richness Guizhou Province reptiles species diversity elevational patterns regional conservation plannin
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Tailoring Microstructure and Microsegregation in a Directionally Solidified Ni-Based SX Superalloy by a Weak Transverse Static Magnetic Field 认领 引用 被引量：4
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作者 Yong Zhao Haijun Su +6 位作者 Guangrao Fan Chenglin Liu Taiwen Huang Wenchao Yang Jun Zhang Lin Liu Hengzhi Fu 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2022年第7期1164-1174,共11页
A weak transverse static magnetic field(WTSMF,0–0.5 T)is applied to the directional solidification process of a DD3 Ni-based SX superalloy,aiming to tailor the microstructure and microsegregation of alloys.The mechan... A weak transverse static magnetic field(WTSMF,0–0.5 T)is applied to the directional solidification process of a DD3 Ni-based SX superalloy,aiming to tailor the microstructure and microsegregation of alloys.The mechanisms of microstructural refinement and microsegregation distribution caused by a WTSMF during directional solidification are discussed.It is shown that the primary dendrite arm spacing is rapidly reduced from 181 to 143μm,and the average size ofγ′phase is significantly refined from 0.85 to 0.25μm as the magnetic field increases from 0 to 0.5 T.At the same time,the volumefractions ofγ/γ′eutectic and the segregation coefficient are also gradually decreased.The 3D numerical simulations of the multiscale convection in liquid phase show that the modifications of the microstructure and microsegregation in DD3 are mainly attributed to the enhanced liquid flow caused by thermoelectric magnetic convection(TEMC)at dendrite/sample scale under the WTSMF.The maximum of the TEMC increases with increasing the magnetic field intensity.This work paves a simple way to optimize the microstructure and microsegregation in directionally solidified Ni-based SX superalloys without changing the processing parameters and composition. 展开更多
关键词 Transverse static magnetic field Microstructure Segregation coefficient Ni-based single-crystal superalloy Thermoelectric magnetic convection
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Correlation Between Phase Stability and Tensile Properties of the Ni-Based Superalloy MAR-M247 认领 引用 被引量：4
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作者 Linxu Li Xiufang Gong +4 位作者 Changshuai Wang Yunsheng Wu Hongyao Yu Haijun Su Lanzhang Zhou 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2021年第6期872-884,共13页
Phase stability and its effect on tensile properties of MAR-M247 alloy have been investigated during thermal exposure at 800–900°C for up to 10,000 h.Detailed investigations reveal that the larger secondaryγ′p... Phase stability and its effect on tensile properties of MAR-M247 alloy have been investigated during thermal exposure at 800–900°C for up to 10,000 h.Detailed investigations reveal that the larger secondaryγ′phase has no obvious growth,but the smaller tertiaryγ′phase obviously coarsens and the coalescence occurs during thermal exposure at 850°C and below.γ′coarsening behavior is consistent with the description of Ostwald ripening theory beforeγ′coalescence.Hf-rich blocky MC carbide shows excellent thermal stability,but Ta-rich script-type MC carbide gradually degenerates via reaction,MC+γ→M23C6+γ′and finally formsγ film around MC and M23C6 carbides.With increasing thermal exposure time,the tensile strength decreases.The ductility first increases and then decreases during exposure at 800°C,but it decreases continuously at 900°C.In addition,the ductility keeps almost constant when the exposure time is longer than 5000 h. 展开更多
关键词 Ni-based superalloy Phase stability Tensile properties Fractural behavior
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Effects of Post-Heat Treatment and Carbide Precipitates on Strength-Ductility Balance of GH3536 Superalloy Prepared by Selective Laser Melting 认领 引用 被引量：2
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作者 Le Xia Haijun Su +8 位作者 Quandong Hu Yinuo Guo Peixin Yang Hongliang Gao Minghui Yu Min Guo Zhuo Zhang Lin Liu Hengzhi Fu 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2024年第10期1667-1679,共13页
The strength and ductility cannot achieve a good tradeoff for some superalloy(e.g.GH3536)prepared by selective laser melting(SLM),which seriously restricts their industrial applications.This work examined the effect o... The strength and ductility cannot achieve a good tradeoff for some superalloy(e.g.GH3536)prepared by selective laser melting(SLM),which seriously restricts their industrial applications.This work examined the effect of post-heat treatment(HT)on the microstructure and mechanical properties of GH3536 produced by SLM.In particular,the influence of carbide precipitate morphology and distribution on strength and ductility of the alloy after heat treatment was discussed.After aging at 650°C(denoted as HT1),the Cr23C6 carbides were distributed in chains.The ductility increased by approximately 31%,while the strength slightly decreased.After aging at 745°C(denoted as HT2),the Cr23C6 carbides were distributed in chains.However,the HT2 samples showed an increase in ductility of~58%and no reduction in strength.As the dislocation density of HT2 sample was higher than that of the HT1 sample,the chain carbides could be pinned to the grain boundaries,consequently improving the ductility but no loss in strength as compared with the as-deposited samples.When the aging temperature was increased to 900°C(denoted as HT3),the carbides were distributed in a discontinuous granular form.As a result,the HT3 samples presented the lowest dislocation density which reduced the strength. 展开更多
关键词 Selective laser melting GH3536 Heat treatment Carbides Strength-ductility
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Enhanced 3D printing and crack control in melt-grown eutectic ceramic composites with high-entropy alloy doping 认领 引用 被引量：9
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作者 Zhonglin Shen Haijun Su +10 位作者 Minghui Yu Yinuo Guo Yuan Liu Hao Jiang Xiang Li Dong Dong Peixin Yang Jiatong Yao Min Guo Zhuo Zhang Wei Ren 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2025年第6期64-78,共15页
As a 3D printing method,laser powder bed fusion(LPBF)technology has been extensively proven to offer significant advantages in fabricating complex structured specimens,achieving ultra-fine microstructures,and enhancin... As a 3D printing method,laser powder bed fusion(LPBF)technology has been extensively proven to offer significant advantages in fabricating complex structured specimens,achieving ultra-fine microstructures,and enhancing performances.In the domain of manufacturing melt-grown oxide ceramics,it encounters substantial challenges in suppressing crack defects during the rapid solidification process.The strategic integration of high entropy alloys(HEA),leveraging the significant ductility and toughness into ceramic powders represents a major innovation in overcoming the obstacles.The ingenious doping of HEA parti-cles preserves the eutectic microstructures of the Al2O3/GdAlO3(GAP)/ZrO2ceramic composite.The high damage tolerance of the HEA alloy under high strain rates enables the absorption of crack energy and alleviation of internal stresses during LPBF,effectively reducing crack initiation and growth.Due to in-creased curvature forces and intense Marangoni convection at the top of the molt pool,particle collision intensifies,leading to the tendency of HEA particles to agglomerate at the upper part of the molt pool.However,this phenomenon can be effectively alleviated in the remelting process of subsequent layer de-position.Furthermore,a portion of the HEA particles partially dissolves and sinks into the molten pool,acting as heterogeneous nucleation particles,inducing the formation of equiaxed eutectic and leading pri-mary phase nucleation.Some HEA particles diffuse into the lamellar ternary eutectic structures,further promoting the refinement of eutectic microstructures due to increased undercooling.The innovative dop-ing of HEA particles has effectively facilitated the fabrication of turbine-structured,conical,and cylindrical ternary eutectic ceramic composite specimens with diameters of about 70 mm,demonstrating significant developmental potential in the field of ceramic composite manufacturing. 展开更多
关键词 Laser powder bed fusion Eutectic ceramic composite High entropy alloy doping
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Synergistic dual-scale laser beams for fabricating high-temperature eutectic ceramic coatings with nano microstructures via LPBF 认领 引用 被引量：1
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作者 Zhonglin Shen Haijun Su +8 位作者 Minghui Yu Peixin Yang Yinuo Guo Yang Cao Hao Jiang Xiang Li Dong Dong Zhuo Zhang Min Guo 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2025年第31期292-306,共15页
This study introduces a novel integrated laser powder bed fusion(LPBF)approach for fabricating high-quality,ultra-high-temperature oxide eutectic ceramic coatings on superalloys to meet the critical demand for improve... This study introduces a novel integrated laser powder bed fusion(LPBF)approach for fabricating high-quality,ultra-high-temperature oxide eutectic ceramic coatings on superalloys to meet the critical demand for improved thermal barrier coatings in high-temperature applications.To resolve the interface bonding challenges between brittle ceramic coatings and ductile superalloys,this method employs two different laser sources:a short-wavelength fiber laser for fabricating the IN718 superalloy substrate and NiCoCrAlY bonding layer,and a long-wavelength CO2 laser for depositing oxide eutectic ceramic coatings.Additionally,the finite element modeling(FEM)is utilized to optimize the preparation of superalloy–ceramic coating composites using LPBF technology,revealing the temperature and stress field distributions during the fabrication process.The resulting in-situ eutectic composite ceramic coatings exhibit a bonding strength of about 29.3 N and a nanoscale microstructure with a eutectic spacing of 97 nm.In high-temperature water-oxygen corrosion tests at 1000℃,the coatings showed no signs of delamination.After 100 h of heat treatment at 500℃,the microstructure experienced only a slight coarsening,maintaining its nanoscale structures.This LPBF fabrication method provides an effective approach for the rapid integrated manufacturing of oxide eutectic ceramic coatings on superalloy substrates,demonstrating significant potential for high temperature applications. 展开更多
关键词 Laser powder bed fusion Ceramic coating FEM simulation Bonding strength
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Surface remelting strategy for enhancing forming quality in laser directed energy deposition of Al2O3/GdAlO3/ZrO2eutectic ceramics:Defect suppression and microstructure evolution 认领 引用 被引量：1
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作者 Shengyang Yu Haijun Su +10 位作者 Hao Jiang Minghui Yu Ruotong Wang Peiyi Zhu Baohao Lu Yun Zhang Yinuo Guo Zhonglin Shen Zhuo Zhang Min Guo Wenchao Yang 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2026年第1期51-66,共16页
The intrinsic brittleness of ceramic materials and the complex temperature field used during laser directed energy deposition(LDED)inevitably lead to the formation of surface and internal defects in the fabricated com... The intrinsic brittleness of ceramic materials and the complex temperature field used during laser directed energy deposition(LDED)inevitably lead to the formation of surface and internal defects in the fabricated components,which significantly affect their subsequent deposition accuracy and mechanical properties.This study systematically investigates the influence of the laser surface remelting(LSR)process on the forming quality of Al2O3/GdAlO3/ZrO2eutectic ceramics prepared via LDED and reveals the underlying mechanisms with the support of finite element method(FEM)simulations and an infrared thermal imager.The new LSR strategy achieves a remarkable reduction of up to 82%in surface roughness by forming a secondary molten pool and mitigating heat accumulation effects.Moreover,the internal crack density and porosity are reduced by 41%and 86%,respectively.Through redistribution and precise control of the energy input,the originally incomplete eutectic microstructure is successfully transformed into an ultrafine eutectic microstructure,thereby effectively mitigating microstructural inhomogeneity,with the eutectic spacing refined to as small as 102 nm.Additionally,the reduction in surface and internal defects increases the relative density of the samples from 89.3%to 95.9%,whereas the microhardness shows maximum improvements of 18%and 11%in the transverse and longitudinal sections,respectively.On this basis,by integrating the LSR process,this study successfully prepared a bulk eutectic ceramic free of obvious macroscopic defects,with dimensions of 45 mm×20 mm×30 mm.The results provide critical insights into the scientific mechanism of the LSR in terms of defect suppression,microstructure evolution regulation,and mechanical property enhancement of eutectic ceramics.This approach is expected to offer a new technical pathway for improving the formation quality of LDED-ed large-size complex oxide eutectic ceramics,as well as other brittle material systems. 展开更多
关键词 laser directed energy deposition(LDED) oxide eutectic ceramics laser surface remelting(LSR) defect suppression
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Mechanical Properties of Al2O3/FeCo Interface under Magnetic Field:A Molecular Dynamics Study 认领 引用
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作者 Chun Wang Haijun Su +2 位作者 Xi Li Wei Ren Yongle Li 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2025年第3期323-333,I0037-I0047,I0109,共11页
Metal-ceramic composites combine the excellent properties of metals and ceramics,which have high strength,stability,and corrosion re-sistance.Al2O3/FeCo composites have been proven to be useful in ap-plications ... Metal-ceramic composites combine the excellent properties of metals and ceramics,which have high strength,stability,and corrosion re-sistance.Al2O3/FeCo composites have been proven to be useful in ap-plications such as catalysts,mi-crowave absorption materials,and enhanced permeability dielectric.The understanding of the mechani-cal properties and dynamics at the atomic scale of the Al2O3/FeCo in-terface can promote the design and exploitment of metal-ceramic composites.In this work,we have obtained Young’s modulus and diffusion coefficient of the Al2O3/FeCo interface using molecular dynamics simulation,elucidated the structural characteristics of the Al2O3/FeCo interface at the atomic scale,and investigated the impact of atomic magnetism and the exter-nal magnetic field on the interface.Simulated results show that Young’s modulus of the Al2O3/FeCo interface is significantly improved compared with pure Al2O3and FeCo alloy at room and high temperatures.When the atomic magnetism and the external magnetic field are applied,Young’s modulus of the Al2O3/FeCo interface further increases to 612 GPa at 300 K and 602 GPa at 500 K.Moreover,the average density,diffusion coefficient,and radial distri-bution function are found to be modified substantially.This study will shed light on the atom-istic investigations of the metal-ceramic composites. 展开更多
关键词 Molecular dynamics Al2O3/FeCo interface Young’s modulus Magnetism Magnetic field Diffusion coefficient
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Enhanced comprehensive properties of stereolithography 3D printed alumina ceramic cores with high porosities by a powder gradation design 认领 引用 被引量：24
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作者 Xiang Li Haijun Su +12 位作者 Dong Dong Di Zhao Yuan Liu Zhonglin Shen Hao Jiang Yinuo Guo Haifang Liu Guangrao Fan Wenchao Yang Taiwen Huang Jun Zhang Lin Liu Hengzhi Fu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第36期264-275,共12页
Ceramic cores with complex structures and optimized properties are critical for hollow turbine blades applied in aeroengines.Compared to traditional methods,additive manufacturing(AM)presents great advantages in formi... Ceramic cores with complex structures and optimized properties are critical for hollow turbine blades applied in aeroengines.Compared to traditional methods,additive manufacturing(AM)presents great advantages in forming complex ceramic cores,but how to balance the porosity and strength is an enormous challenge.In this work,alumina ceramic cores with high porosity,moderate strength,and low high-temperature deflection were prepared using stereolithography(SLA)3D printing by a novel powder gradation design strategy.The contradiction between porosity and flexural strength is well adjusted when the mass ratio of the coarse,medium,and fine particles is 2:1:1 and the sintering temperature is 1600℃.The fracture mode of coarse particles in sintered SLA 3D printing ceramic transforms from intergranular fracture to transgranular fracture with the increase of sintering temperature and the proportion of fine powders in powder system.The sintered porosity has a greater influence on the high-temperature deflection of SLA 3D printed ceramic cores than grain size.On this basis,a"non-skeleton"microstructure model of SLA 3D printed alumina ceramic cores is created to explain the relationship between the sintering process and properties.As a result,high porosity(36.4%),appropriate strength(50.1 MPa),and low high-temperature deflection(2.27 mm)were achieved by optimizing particle size gradation and sintering process,which provides an insight into the important enhancement of the comprehensive properties of SLA 3D printed ceramic cores. 展开更多
关键词 Ceramic cores Stereolithography(SLA) Powder gradation design Sintering temperature Comprehensive properties
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Unique strength-ductility balance of AlCoCrFeNi2.1eutectic high entropy alloy with ultra-fine duplex microstructure prepared by selective laser melting 认领 引用 被引量：20
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作者 Yinuo Guo Haijun Su +5 位作者 Haotian Zhou Zhonglin Shen Yuan Liu Jun Zhang Lin Liu Hengzhi Fu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第16期298-306,共9页
As a typical dual-phase eutectic high entropy alloy(EHEA),AlCoCrFeNi2.1can achieve the fair matching of strength and ductility,which has attracted wide attention.However,the engineering applications of as-cast AlCo... As a typical dual-phase eutectic high entropy alloy(EHEA),AlCoCrFeNi2.1can achieve the fair matching of strength and ductility,which has attracted wide attention.However,the engineering applications of as-cast AlCoCrFeNi2.1EHEAs still face challenges,such as coarse grain and low yield strength resulting from low solidification rate and temperature gradient.In this study,selective laser melting(SLM)was introduced into the preparation of AlCoCrFeNi2.1EHEA to realize unique strength-ductility balance,with emphasis on investigating the effects of processing parameters on its eutectic microstructure and properties.The results show that the SLM-ed samples exhibit a completely eutectic structure consisting of ultra-fine face-centered cubic(FCC)and ordered body-centered cubic(B2)phases,and the duplex microstructure undergoes a morphological evolution from lamellar structure to cellular structure as laser energy input reducing.The SLM-ed AlCoCrFeNi2.1EHEA presents an excellent match of high tensile strength(1271 MPa),yield strength(966 MPa),and good ductility(22.5%)at room temperature,which are significantly enhanced by the ultra-fine grains and heterogeneous structure due to rapid solidification rate and high temperature gradient during SLM.Especially,the yield strength increment of~50%is realized with no loss in ductility as compared with the as-cast samples with the same composition.On this basis,the precise complex component with excellent mechanical properties is well achieved.This work paves the way for the performance improvement and complex parts preparation of EHEA by microstructural design using laser additive manufacturing. 展开更多
关键词 Selective laser melting High-entropy alloy Eutectic structure Rapid solidification Tensile properties
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Preparation of large-size Al2O3/GdAlO3/ZrO2ternary eutectic ceramic rod by laser directed energy deposition and its microstructure homogenization mechanism 认领 引用 被引量：18
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作者 Haifang Liu Haijun Su +7 位作者 Zhonglin Shen Di Zhao Yuan Liu Yinuo Guo Min Guo Jun Zhang Lin Liu Hengzhi Fu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第26期218-223,共6页
Laser 3D printing based on melt growth has great potential in rapid preparation of Al2O3-based eutectic ce ramics.In this work,la rge-scale Al2O3/GdAlO3/ZrO2ternary eutectic ceramic rod with diameter... Laser 3D printing based on melt growth has great potential in rapid preparation of Al2O3-based eutectic ce ramics.In this work,la rge-scale Al2O3/GdAlO3/ZrO2ternary eutectic ceramic rod with diameter of 4-5 mm and height higher than 250 mm was additively manufactured by laser directed energy deposition.Especially,heat treatment was applied to eliminate the microstructure heterogeneity in the as-deposited eutectic ceramic,and the microstructure homogenization mechanism was studied in depth.The results indicate that colonies and banded structures completely disappear after the heat treatment,producing a homogeneous network eutectic structure.The microstructure homogenization is revealed to experience three stages of discontinuous coarsening,continuous coarsening and microstructure coalescence.Additionally,it is found that the eutectic spacing linearly increases with the heat treatment time,meaning that the coarsening behavior of the laser 3D-printed Al2O3/GdAlO3/ZrO2eutectic ceramic satisfies well with the Graham-Kraft model. 展开更多
关键词 Oxide eutectic ceramic Laser 3D printing Melt growth Heat treatment Microstructure homogenization
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Distribution control and formation mechanism of gas inclusions in directionally solidified Al2O3-Er3Al5O12-ZrO2 ternary eutectic ceramic by laser floating zone melting 认领 引用 被引量：11
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作者 Haijun Su Yuan Liu +8 位作者 Qun Ren Zhonglin Shen Haifang Liu Di Zhao Guangrao Fan Min Guo Jun Zhang Lin Liu Hengzhi Fu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第7期21-27,共7页
Distribution control and formation mechanism of gas inclusions formed in directionally solidified Al2O3-Er3Al5O12-ZrO2 eutectic ceramic rods are explored during laser floating zone melting. In atmospheric environment,... Distribution control and formation mechanism of gas inclusions formed in directionally solidified Al2O3-Er3Al5O12-ZrO2 eutectic ceramic rods are explored during laser floating zone melting. In atmospheric environment, highly-dense bubble-free eutectic rods are well fabricated at low solidification rate(<25μm/s). Gas inclusions form intermittently when the solidification rate is in the range of 25-50 μm/s,but produce continuously at higher solidification rates(100-200 μm/s). The gas inclusions exhibit an elongated finger-like pattern along the growth direction, which of the maximum value of diameter first increases and then decreases with increasing the solidification rate. Meanwhile, the volume fraction of gas inclusions increased gradually with the solidification rate. Based on the effect of surface tension gradient, heterogeneous nucleation of gas bubbles is evaluated to be the primary formation mechanism of gas inclusions. 展开更多
关键词 Directional solidification Gas inclusions Eutectic oxide Laser floating zone melting Formation mechanism
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New approach to preparing near zero shrinkage alumina ceramic cores with excellent properties by vat photopolymerization 认领 引用 被引量：9
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作者 Xiang Li Haijun Su +7 位作者 Dong Dong Hao Jiang Yuan Liu Zhonglin Shen Yinuo Guo Shuqi Hao Zhuo Zhang Min Guo 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第26期61-72,共12页
Vat photopolymerization(VPP)3D printing technology has broken through mold limitations and shown great potential to manufacture complex-structured ceramic cores for turbine blades.However,improving dimensional accurac... Vat photopolymerization(VPP)3D printing technology has broken through mold limitations and shown great potential to manufacture complex-structured ceramic cores for turbine blades.However,improving dimensional accuracy is difficult for the VPP 3D printed parts due to the high contraction deformation.Reducing shrinkage is a key challenge for developing 3D-printed ceramic cores.In this study,3D-printed alumina ceramic cores with near-zero shrinkage in the X direction were achieved for the first time using a novel approach that was called atmosphere-controlled in-situ oxidation of aluminum powder.The in-situ oxidation reaction of the aluminum powder was creatively tuned by changing the atmosphere transition temperature from argon to air.Then,the microstructure and properties of the ceramic core could be controlled by the liquid-phase sintering with the participation of atmosphere-protected molten aluminum.As a result,the pore size of the ceramic cores was significantly increased by almost ten times,but the bonding strength of the grains was also increased.In addition,the powder consolidation generated by the action of molten aluminum was considered to be an important reason for reducing the linear shrinkage of ceramic cores.Under the optimized parameters,the linear shrinkage of the ceramic cores was as low as 0.3%in the X direction.The high apparent porosity(45.02%)and flexural strength(72.7 MPa)of the alumina ceramic cores were realized at the same time.The in-situ control of sintering by changing the atmosphere will be a creative method for regulating the properties of ceramic materials. 展开更多
关键词 Near-zero shrinkage Vat photopolymerization Alumina ceramic cores Post-processing regime Aluminum powder
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