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Printability disparities in heterogeneous material combinations via laser directed energy deposition:a comparative study
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作者 Jinsheng Ning Lida Zhu +9 位作者 Shuhao Wang Zhichao Yang Peihua Xu Pengsheng Xue Hao Lu Miao Yu Yunhang Zhao Jiachen Li Susmita Bose Amit Bandyopadhyay 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第2期389-405,共17页
Additive manufacturing provides achievability for the fabrication of bimetallic and multi-material structures;however,the material compatibility and bondability directly affect the parts’formability and final quality... Additive manufacturing provides achievability for the fabrication of bimetallic and multi-material structures;however,the material compatibility and bondability directly affect the parts’formability and final quality.It is essential to understand the underlying printability of different material combinations based on an adapted process.Here,the printability disparities of two common and attractive material combinations(nickel-and iron-based alloys)are evaluated at the macro and micro levels via laser directed energy deposition(DED).The deposition processes were captured using in situ high-speed imaging,and the dissimilarities in melt pool features and track morphology were quantitatively investigated within specific process windows.Moreover,the microstructure diversity of the tracks and blocks processed with varied material pairs was comparatively elaborated and,complemented with the informative multi-physics modeling,the presented non-uniformity in mechanical properties(microhardness)among the heterogeneous material pairs was rationalized.The differences in melt flow induced by the unlike thermophysical properties of the material pairs and the resulting element intermixing and localized re-alloying during solidification dominate the presented dissimilarity in printability among the material combinations.This work provides an in-depth understanding of the phenomenological differences in the deposition of dissimilar materials and aims to guide more reliable DED forming of bimetallic parts. 展开更多
关键词 directed energy deposition PRINTABILITY microstructure MICROHARDNESS bimetallic parts
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Effect of hot isostatic pressure on the microstructure and tensile properties of γ'-strengthened superalloy fabricated through induction-assisted directed energy deposition
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作者 Jianjun Xu Hanlin Ding +1 位作者 Xin Lin Feng Liu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第5期1089-1097,共9页
The microstructure characteristics and strengthening mechanism of Inconel738LC(IN-738LC) alloy prepared by using induction-assisted directed energy deposition(IDED) were elucidated through the investigation of samples... The microstructure characteristics and strengthening mechanism of Inconel738LC(IN-738LC) alloy prepared by using induction-assisted directed energy deposition(IDED) were elucidated through the investigation of samples subjected to IDED under 1050℃ preheating with and without hot isostatic pressing(HIP,1190℃,105 MPa,and 3 h).Results show that the as-deposited sample mainly consisted of epitaxial columnar crystals and inhomogeneously distributed γ’ phases in interdendritic and dendritic core regions.After HIP,grain morphology changed negligibly,whereas the size of the γ’ phase became increasingly even.After further heat treatment(HT,1070℃,2 h + 845℃,24 h),the γ’ phase in the as-deposited and HIPed samples presented a bimodal size distribution,whereas that in the as-deposited sample showed a size that remained uneven.The comparison of tensile properties revealed that the tensile strength and uniform elongation of the HIP + HTed sample increased by 5% and 46%,respectively,due to the synergistic deformation of bimodal γ’phases,especially large cubic γ’ phases.Finally,the relationship between phase transformations and plastic deformations in the IDEDed sample was discussed on the basis of generalized stability theory in terms of the trade-off between thermodynamics and kinetics. 展开更多
关键词 directed energy deposition Ni-based superalloys high-temperature preheating hot isostatic pressing MICROSTRUCTURE tensile properties
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Cracking on a nickel-based superalloy fabricated by direct energy deposition
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作者 Xue Zhang Ya-hang Mu +4 位作者 Liang Ma Jing-jing Liang Yi-zhou Zhou Xiao-feng Sun Jin-guo Li 《China Foundry》 SCIE EI CAS CSCD 2024年第4期311-318,共8页
Cracks have consistently been a significant challenge limiting the development of additive manufactured nickel-based superalloys.It is essential to investigate the location of cracks and their forming mechanism.This s... Cracks have consistently been a significant challenge limiting the development of additive manufactured nickel-based superalloys.It is essential to investigate the location of cracks and their forming mechanism.This study extensively examines the impact of solidification process,microstructural evolution,and stress concentration on crack initiation during direct energy deposition(DED).The results emphasize that the crack formation is significantly related to large-angle grain boundaries,rapid cooling rates.Cracks caused by large-angle grain boundaries and a fast-cooling rate predominantly appear near the edge of the deposited samples.Liquation cracks are more likely to form near the top of the deposited sample,due to the presence ofγ/γ'eutectics.The secondary dendritic arm and the carbides in the interdendritic regions can obstruct liquid flow during the final stage of solidification,which results in the formation of solidification cracks and voids.This work paves the way to avoid cracks in nickel-based superalloys fabricated by DED,thereby enhancing the performance of superalloys. 展开更多
关键词 LOCATION cracks direct energy deposition nickel-based superalloys
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Formation mechanism of inherent spatial heterogeneity of microstructure and mechanical properties of NiTi SMA prepared by laser directed energy deposition 被引量:3
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作者 MengJie Luo Ruidi Li +4 位作者 Dan Zheng JingTao Kang HuiTing Wu ShengHua Deng PengDa Niu 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2023年第3期548-567,共20页
Ni51Ti49 at.%bulk was additively manufactured by laser-directed energy deposition(DED)to reveal the microstructure evolution,phase distribution,and mechanical properties.It is found that the localized remelting,reheat... Ni51Ti49 at.%bulk was additively manufactured by laser-directed energy deposition(DED)to reveal the microstructure evolution,phase distribution,and mechanical properties.It is found that the localized remelting,reheating,and heat accumulation during DED leads to the spatial heterogeneous distribution of columnar crystal and equiaxed crystal,a gradient distribution of Ni4Ti3 precipitates along the building direction,and preferential formation of Ni4Ti3 precipitates in the columnar zone.The austenite transformation finish temperature(Af)varies from-12.65℃(Z=33 mm)to 60.35℃(Z=10 mm),corresponding to tensile yield strength(σ0.2)changed from 120±30 MPa to 570±20 MPa,and functional properties changed from shape memory effect to superelasticity at room temperature.The sample in the Z=20.4 mm height has the best plasticity of 9.6%and the best recoverable strain of 4.2%.This work provided insights and guidelines for the spatial characterization of DEDed NiTi. 展开更多
关键词 shape memory alloy gradient functional materials laser directed energy deposition spatial heterogeneity additive manufacturing mechanical properties
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Review on laser directed energy deposited aluminum alloys 被引量:2
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作者 Tian-Shu Liu Peng Chen +7 位作者 Feng Qiu Hong-Yu Yang Nicholas Tan Yew Jin Youxiang Chew Di Wang Ruidi Li Qi-Chuan Jiang Chaolin Tan 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第2期84-131,共48页
Lightweight aluminum(Al)alloys have been widely used in frontier fields like aerospace and automotive industries,which attracts great interest in additive manufacturing(AM)to process high-value Al parts.As a mainstrea... Lightweight aluminum(Al)alloys have been widely used in frontier fields like aerospace and automotive industries,which attracts great interest in additive manufacturing(AM)to process high-value Al parts.As a mainstream AM technique,laser-directed energy deposition(LDED)shows good scalability to meet the requirements for large-format component manufacturing and repair.However,LDED Al alloys are highly challenging due to their inherent poor printability(e.g.low laser absorption,high oxidation sensitivity and cracking tendency).To further promote the development of LDED high-performance Al alloys,this review offers a deep understanding of the challenges and strategies to improve printability in LDED Al alloys.The porosity,cracking,distortion,inclusions,element evaporation and resultant inferior mechanical properties(worse than laser powder bed fusion)are the key challenges in LDED Al alloys.Processing parameter optimizations,in-situ alloy design,reinforcing particle addition and field assistance are the efficient approaches to improving the printability and performance of LDED Al alloys.The underlying correlations between processes,alloy innovation,characteristic microstructures,and achievable performances in LDED Al alloys are discussed.The benchmark mechanical properties and primary strengthening mechanism of LDED Al alloys are summarized.This review aims to provide a critical and in-depth evaluation of current progress in LDED Al alloys.Future opportunities and perspectives in LDED high-performance Al alloys are also outlined. 展开更多
关键词 additive manufacturing laser directed energy deposition(LDED) aluminum alloys PRINTABILITY aluminum matrix composite auxiliary fields mechanical properties
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Effect of wire-arc directed energy deposition on the microstructural formation and age-hardening response of the Mg-9Al-1Zn(AZ91)alloy
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作者 Gloria Graf Petra Spoerk-Erdely +4 位作者 Emad Maawad Michael Burtscher Daniel Kiener Helmut Clemens Thomas Klein 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第6期1944-1958,共15页
In recent years,wire-arc directed energy deposition(wa DED),which is also commonly known as wire-arc additive manufacturing(WAAM),has emerged as a promising new fabrication technique for magnesium alloys.The major rea... In recent years,wire-arc directed energy deposition(wa DED),which is also commonly known as wire-arc additive manufacturing(WAAM),has emerged as a promising new fabrication technique for magnesium alloys.The major reason for this is the possibility of producing parts with a complex geometry as well as a fine-grained microstructure.While the process has been shown to be applicable for Mg-Al-Zn alloys,there is still a lack of knowledge in terms of the influence of the WAAM process on the age-hardening response.Consequently,this study deals with the aging response of a WAAM AZ91 alloy.In order to fully understand the mechanisms during aging,first,the as-built condition was analyzed by means of high-energy X-ray diffraction(HEXRD)and scanning electron microscopy.These investigations revealed a finegrained,equiaxed microstructure with adjacent areas of alternating Al content.Subsequently,the difference between single-and double-step aging as well as conventional and direct aging was studied on the as-built WAAM AZ91 alloy for the first time.The aging response during the various heat treatments was monitored via in situ HEXRD experiments.Corroborating electron microscopy and hardness studies were conducted.The results showed that the application of a double-step aging heat treatment at 325℃with pre-aging at 250℃slightly improves the mechanical properties when compared to the single-step heat treatment at 325℃.However,the hardness decreases considerably after the pre-aging step.Thus,aging at lower temperatures is preferable within the investigated temperature range of 250-325℃.Moreover,no significant difference between the conventionally aged and directly aged samples was found.Lastly,the specimens showed enhanced precipitation kinetics during aging as compared to cast samples.This could be attributed to a higher amount of nucleation sites and the particular temperature profile of the solution heat treatment. 展开更多
关键词 Wire-arc directed energy deposition Additive manufacturing High-energy X-ray diffraction Synchrotron Mg-Al-Zn alloys AGE-HARDENING
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Revealing precipitation behavior and mechanical response of wire-arc directed energy deposited Mg-Gd-Y-Zr alloy by tailoring aging procedures
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作者 Xinzhi Li Xuewei Fang +8 位作者 Zhiyan Zhang Shahid Ghafoor Ruikai Chen Yi Liu Kexin Tang Kai Li Minghua Ma Jiahao Shang Ke Huang 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第4期176-200,共25页
Mg-Gd-Y-Zr alloy,as a typical magnesium rare-earth(Mg-RE)alloy,is gaining popularity in the advanced equipment manufacturing fields owing to its noticeable age-hardening properties and high specific strength.However,i... Mg-Gd-Y-Zr alloy,as a typical magnesium rare-earth(Mg-RE)alloy,is gaining popularity in the advanced equipment manufacturing fields owing to its noticeable age-hardening properties and high specific strength.However,it is extremely challenging to prepare wrought components with large dimensions and complex shapes because of the poor room-temperature processability of Mg-Gd-Y-Zr alloy.Herein,we report a wire-arc directed energy deposited(DED)Mg-10.45Gd-2.27Y-0.52Zr(wt.%,GW102K)alloy with high RE content presenting a prominent combination of strength and ductility,realized by tailored nanoprecipitates through an optimized heat treatment procedure.Specifically,the solution-treated sample exhibits excellent ductility with an elongation(EL)of(14.6±0.1)%,while the aging-treated sample at 200°C for 58 h achieves an ultra-high ultimate tensile strength(UTS)of(371±1.5)MPa.Besides,the aging-treated sample at 250°C for 16 h attains a good strength-ductility synergy with a UTS of(316±2.1)MPa and a EL of(8.5±0.1)%.Particularly,the evolution mechanisms of precipitation response induced by various aging parameters and deformation behavior caused by nanoprecipitates type were also systematically revealed.The excellent ductility resulted from coordinating localized strains facilitated by active slip activity.And the ultra-high strength should be ascribed to the dense nano-β'hampering dislocation motion.Additionally,the shearable nano-β1 contributed to the good strength-ductility synergy.This work thus offers insightful understanding into the nanoprecipitates manipulation and performance tailoring for the wire-arc DED preparation of large-sized Mg-Gd-Y-Zr components with complex geometries. 展开更多
关键词 wire-arc directed energy deposition Mg-Gd-Y-Zr alloy precipitation response prominent strength-ductilitycombination deformation mechanism
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Microstructure and mechanical property of additively manufactured NiTi alloys:A comparison between selective laser melting and directed energy deposition 被引量:10
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作者 ZHENG Dan LI Rui-di +4 位作者 YUAN Tie-chui XIONG Yi SONG Bo WANG Jia-xing SU Ya-dong 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第4期1028-1042,共15页
NiTi shape memory alloy(SMA)with nominal composition of Ni 50.8 at%and Ti 49.2 at%was additively manufactured(AM)by selective laser melting(SLM)and laser directed energy deposition(DED)for a comparison study,with emph... NiTi shape memory alloy(SMA)with nominal composition of Ni 50.8 at%and Ti 49.2 at%was additively manufactured(AM)by selective laser melting(SLM)and laser directed energy deposition(DED)for a comparison study,with emphasis on its phase composition,microstructure,mechanical property and deformation mechanism.The results show that the yield strength and ductility obtained by SLM are 100 MPa and 8%,respectively,which are remarkably different from DED result with 700 MPa and 2%.The load path of SLM sample presents shape memory effect,corresponding to martensite phase detected by XRD;while the load path of DED presents pseudo-elasticity with austenite phase.In SLM sample,fine grain and hole provide a uniform deformation during tensile test,resulting in a better elongation.Furthermore,the nonequilibrium solidification was studied by a temperature field simulation to understand the difference of the two 3D printing methods.Both temperature gradient G and growth rate R determine the microstructure and phase in the SLM sample and DED sample,which leads to similar grain morphologies because of similar G/R.While higher G×R of SLM leads to a finer grain size in SLM sample,providing enough driving force for martensite transition and subsequently changing texture compared to DED sample. 展开更多
关键词 Ni50.8Ti49.2 shape memory alloy additive manufacturing selective laser melting laser directed energy deposition mechanical properties
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Numerical Simulation of Radial and Angular Distribution of γ-Ray's Energy Deposition in Scintillation Optical Fibre
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作者 唐世彪 阴泽杰 +1 位作者 唐瑜 黄环 《Plasma Science and Technology》 SCIE EI CAS CSCD 2006年第4期406-408,共3页
Angular and radial distributions of the energy deposition of γ-ray radiation in scintillation optical fibres are simulated and analysed using the Geant4 system. The results show a linear relation between the energy d... Angular and radial distributions of the energy deposition of γ-ray radiation in scintillation optical fibres are simulated and analysed using the Geant4 system. The results show a linear relation between the energy deposition and the radius of the fibres. The deposition is roughly inversely proportional to sinθ with θ the incident angle relative to the fibre axis. The results could provide corrections to the measurements of the scintillation fibres used in monitoring the γ-ray radiation. 展开更多
关键词 GEANT4 scintillation optical fibre energy deposition
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High-temperature tribological performance of functionally graded Stellite 6/WC metal matrix composite coatings manufactured by laser-directed energy deposition
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作者 Marta OSTOLAZA Alaitz ZABALA +3 位作者 Jon Inaki ARRIZUBIETA Iñigo LLAVORI Nagore OTEGI Aitzol LAMIKIZ 《Friction》 SCIE EI CAS CSCD 2024年第3期522-538,共17页
Wear-driven tool failure is one of the main hurdles in the industry.This issue can be addressed through surface coating with ceramic-reinforced metal matrix composites.However,the maximum ceramic content is limited by... Wear-driven tool failure is one of the main hurdles in the industry.This issue can be addressed through surface coating with ceramic-reinforced metal matrix composites.However,the maximum ceramic content is limited by cracking.In this work,the tribological behaviour of the functionally graded WC-ceramic-particlereinforced Stellite 6 coatings is studied.To that end,the wear resistance at room temperature and 400°C is investigated.Moreover,the tribological analysis is supported by crack sensitivity and hardness evaluation,which is of utmost importance in the processing of composite materials with ceramic-particle-reinforcement.Results indicate that functionally graded materials can be employed to increase the maximum admissible WC content,hence improving the tribological behaviour,most notably at high temperatures.Additionally,a shift from abrasive to oxidative wear is observed in high-temperature wear testing. 展开更多
关键词 FRICTION coating metal matrix composite functionally graded materials high temperature laserdirected energy deposition
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Enhanced strength-ductility synergy of magnesium alloy fabricated by ultrasound assisted directed energy deposition
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作者 Xinzhi Li Xuewei Fang +2 位作者 Mugong Zhang Binglin Wang Ke Huang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第11期247-261,共15页
Investigations on the fabrication of large-size lightweight Mg alloy components by wire-arc directed en-ergy deposition(DED)are steadily flourishing.Nevertheless,most of these components still suffer from inferior per... Investigations on the fabrication of large-size lightweight Mg alloy components by wire-arc directed en-ergy deposition(DED)are steadily flourishing.Nevertheless,most of these components still suffer from inferior performance due to internal defects and inherent columnar grains.Herein,external ultrasound fields with different powers were successfully introduced into the wire-arc DED of AZ31 Mg alloy.The microstructure,defects,and mechanical properties of the fabricated components were carefully charac-terized and compared.The results show that the external ultrasound fields lead to decreased porosity,complete columnar to equiaxed transition(CET),and enhanced performance.Consequently,the UA90 samples exhibited a remarkable increase of~30%,~45%,and~189%in yield strength,ultimate tensile strength,and elongation,respectively.The dominant mechanisms of enhanced strength-ductility synergy were analyzed in detail.This study thus sheds new light on wire-arc DED of Mg alloy components with excellent performance via external ultrasound fields. 展开更多
关键词 Wire-arc directed energy deposition External ultrasound field Defects Microstructure evolution Strength-ductility synergy
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An experimental study on effects of temperature gradient on microstructure of a 308L stainless steel manufactured by directed energy deposition
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作者 Ting Dai De-yu Gu +3 位作者 Yu-wen Qiu Wei Guo Hui Ding Yi-wei Sun 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2024年第8期2031-2040,共10页
The effect of spatial temperature gradient on the microstructural evolution of a 308L stainless steel during the directed energy deposition(DED)process was experimentally investigated.A novel cooling system was design... The effect of spatial temperature gradient on the microstructural evolution of a 308L stainless steel during the directed energy deposition(DED)process was experimentally investigated.A novel cooling system was designed and incorporated to a DED system in order to control the temperature gradient along the deposition direction during solidification.During deposition,the workpiece was placed on a lifting platform,and as the deposition process proceeded,the platform and workpiece were gradually lowered into cooling water so that the temperature gradient along the deposition direction could be controlled and maintained stable during the deposition process.The microstructure characterization results indicated that a deposition strategy with higher G and G/R values(where G is temperature gradient and R is solidification rate)produced finer cellular grains that were better aligned with the deposition direction,while a deposition strategy with lower G and G/R values produced columnar grains with larger primary arm spacing and less aligned with the deposition direction. 展开更多
关键词 Additive manufacturing Directed energy deposition Stainless steel MICROSTRUCTURE Temperature gradient
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Pore Formation Mechanism in W-C Hard Coatings Using Directed Energy Deposition on Tungsten Alloy
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作者 Xinrui Zhang Weijie Fu +3 位作者 Chen Wang Zhenglong Lei Haoran Sun Xudong Li 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2024年第1期89-101,共13页
Porosity is a common phenomenon and can significantly hinder the quality of the coating.Here,the pore formation mechanism and the characteristics of the single tracks of the W-C coating using directed energy depositio... Porosity is a common phenomenon and can significantly hinder the quality of the coating.Here,the pore formation mechanism and the characteristics of the single tracks of the W-C coating using directed energy deposition(DED)are systematically investigated.The forming quality of the tracks,the distribution of the pores,and the elemental distribution near the pores are analyzed by the observations of the cross-sections of the tracks.The temperature field of the melt pool is discussed comprehensively to reveal the pore formation mechanism.The results confirm that Ni and Co evaporated during the DED process due to the high temperature of the melt pool.Pores were continuously produced adjacent to the fusion line when the melt pool was about to solidify since the temperature at the solidification front was higher than the boiling point of Ni.The vaporization area at the fusion line was proposed,where Ni could also evaporate at the time the melt pool started to solidify.The relationship between the solidification rate,the size of the vaporization area and the DED parameters(laser power and scanning speed)was established to discuss the causes of severe pores above the fusion line.This work contains a practical guide to reduce or eliminate the porosity in the coating preparation process on the surface of the tungsten alloy. 展开更多
关键词 Directed energy deposition(DED)process Tungsten alloy W-C coating Pores Binder phase
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Two-dimensional particle-in-cell modeling of blow-off impulse by X-ray irradiation
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作者 Ruibo Li Jin-Long Jiao +3 位作者 Hui Luo Dezhi Zhang Dengwang Wang Kai Wang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第3期53-69,共17页
Space objects such as spacecraft or missiles may be exposed to intense X-rays in outer space,leading to severe damage.The reinforcement of these objects to reduce the damage caused by X-ray irradiation is a significan... Space objects such as spacecraft or missiles may be exposed to intense X-rays in outer space,leading to severe damage.The reinforcement of these objects to reduce the damage caused by X-ray irradiation is a significant concern.The blow-off impulse(BOI)is a crucial physical quantity for investigating material damage induced by X-ray irradiation.However,the accurate calculation of BOI is challenging,particularly for large deformations of materials with complex configurations.In this study,we develop a novel two-dimensional particle-in-cell code,Xablation2D,to calculate BOIs under far-field X-ray irradiation.This significantly reduces the dependence of the numerical simulation on the grid shape.The reliability of this code is verified by simulation results from open-source codes,and the calculated BOIs are consistent with the experimental and analytical results. 展开更多
关键词 X-ray irradiation energy deposition Blow-off impulse Particle in cells
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Influence of tungsten particle size on microstructure and mechanical properties of high strength and tough tungsten particle-reinforced nickel-based composites by laser-direct energy deposition
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作者 Wenji Song Dengzhi Wang +7 位作者 Congwen Tang Pengfei Sun Jiaxing Yang Zhidong Xu Tao Lai Jianqiang Gong Qianwu Hu Xiaoyan Zeng 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第5期213-227,共15页
Tungsten(W)particle-reinforced nickel(Ni)-based composites were fabricated via laser-direct energy de-position(L-DED).The influence of the W particle size on the microstructure and mechanical properties of the deposit... Tungsten(W)particle-reinforced nickel(Ni)-based composites were fabricated via laser-direct energy de-position(L-DED).The influence of the W particle size on the microstructure and mechanical properties of the deposited samples was systematically studied.The results indicate that refining the W particle size could refine theγ-Ni grains and subgrains,thin the(Ni,Cr)_(4)W interface layer,and increase the disloca-tion density of the intergranular matrix,thus improving the tensile strength and elongation of the L-DED samples.As W particle size decreased from 75 to 150μm to 6.5-12μm,the tensile strength and elonga-tion of the deposited samples increased by 150 MPa and 2.9 times to 1347.6±15.7 MPa and 17.5±0.4%,respectively.Based on the properties of the interface(Ni,Cr)_(4)W,a load-transfer efficiency factor suitable for this composite was proposed and the load-transfer strengthening formula was optimized.A quanti-tative analysis of the strengthening mechanisms was established considering load-transfer strengthening,Hall-Petch strengthening,thermal-mismatch strengthening,and solid-solution strengthening.The calcu-lated contribution of each strengthening mechanism to the yield strength and theoretical calculations were in good agreement with the experimental data.The article breaks the bottleneck of poor plasticity of W particle-reinforced Ni-based composites prepared by L-DED and provides a theoretical basis for the construction design of W particle-reinforced Ni-based composites with excellent mechanical properties. 展开更多
关键词 Laser-direct energy deposition(L-DED) Tungsten particle reinforcements Mechanical property Strengthening mechanism
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Effect of Multiple Thermal Cycles on Microstructure and Mechanical Properties of Cu Modified Ti64 Thin Wall Fabricated by Wire-Arc Directed Energy Deposition
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作者 Zidong Lin Xuefeng Zhao +5 位作者 Wei Ya Yan Li Zhen Sun Shiwei Han Xiaoyang Peng Xinghua Yu 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2024年第11期1875-1890,共16页
This study investigated the effect of thermal cycles on Cu-modified Ti64 thin-walled components deposited using the wire-arc directed energy deposition(wire-arc DED)process.For the samples before and after experiencin... This study investigated the effect of thermal cycles on Cu-modified Ti64 thin-walled components deposited using the wire-arc directed energy deposition(wire-arc DED)process.For the samples before and after experiencing thermal cycles,it was found that both microstructures consisted of priorβ,grain boundaryα(GBα),and basketweave structures containingα+βlamellae.Thermal cycles realized the refinement ofαlaths,the coarsening of priorβgrains andβlaths,while the size and morphology of continuously distributed GBαremained unchanged.The residualβcontent was increased after thermal cycles.Compared with the heat-treated sample with nanoscale Ti2Cu formed,short residence time in high temperature caused by the rapid cooling rate of thermal cycles restricted Ti2Cu formation.No formation of brittle Ti2Cu means that only grain refinement strengthening and solid-solution strengthening matter.The yield strength increased from 809.9 to 910.85 MPa(12.46%increase).Among them,the main contribution from solid solution strengthening(~51 MPa)was due to the elemental redistribution effect betweenαandβphases caused by thermal cycles through quantitative analysis.The ultimate tensile strength increased from 918.5 to 974.22 MPa(6.1%increase),while fracture elongation increased from 6.78 to 10.66%(57.23%increase).Grain refinement ofαlaths,the promotedα′martensite decomposition,decreased aspect ratio,decreased Schmid factor,and local misorientation change ofαlaths are the main factors in improved ductility.Additionally,although the fracture modes of the samples in the top and middle regions are both brittle-ductile mixed fracture mode,the thermal cycles still contributed to an improvement in tensile ductility. 展开更多
关键词 Wire-arc directed energy deposition(wire-arc DED) Ti64-1.2Cu thin wall Thermal cycles Microstructure variation Mechanical properties
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The Distortion of Energy Deposit Distribution of (12)~C Ions in Water
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作者 宋玉收 颜强 +2 位作者 井田 席印印 刘辉兰 《Plasma Science and Technology》 SCIE EI CAS CSCD 2012年第7期665-669,共5页
The transport process of 12C ions in water was studied with SRIM code and Geant4 toolkit. The SRIM results indicate that the transverse diffusion of 12C ion beam causes distortion of energy deposit along the beam dire... The transport process of 12C ions in water was studied with SRIM code and Geant4 toolkit. The SRIM results indicate that the transverse diffusion of 12C ion beam causes distortion of energy deposit along the beam direction. The distortion becomes more notable as the transverse diffusion increases. The simulation results of Geant4 indicate that the influence of secondary fragments on energy deposit distribution would be the main factor causing the distortion in higher energy range. In the region adjacent to the beam line where the contribution from 12C ions domi- nates, the contributions from secondary fragments are ignorable. The further from the beam axis the region locates, the larger the contributions from secondary fragments, until the contributions from secondary fragments are ignorable. The further from the beam axis the region locates, the larger the contributions from secondary fragments, until the contributions from secondary frag- ments exceed that of 12C. Among all the secondary fragments, the contributions of H, He and B ions are mostly notable. It is also found that some positron-emitting secondary fragments could be very useful for position emitting tomography (PET). 展开更多
关键词 12C ions simulation secondary fragments energy deposit distribution
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A review on additive/subtractive hybrid manufacturing of directed energy deposition(DED)process
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作者 Mohammadreza Lalegani Dezaki Ahmad Serjouei +4 位作者 Ali Zolfagharian Mohammad Fotouhi Mahmoud Moradi M.K.A.Ariffin Mahdi Bodaghi 《Advanced Powder Materials》 2022年第4期39-58,共20页
Additive manufacturing(AM)processes are reliable techniques to build highly complex metallic parts.Direct energy deposition(DED)is one of the most common technologies to 3D print metal alloys.Despite a wide range of l... Additive manufacturing(AM)processes are reliable techniques to build highly complex metallic parts.Direct energy deposition(DED)is one of the most common technologies to 3D print metal alloys.Despite a wide range of literature that has discussed the ability of DED in metal printing,weak binding,poor accuracy,and rough surface still exist in final products.Thus,limitations in 3D printing of metal powder and wire indicate post-processing techniques required to achieve high quality in both mechanical properties and surface quality.Therefore,hybrid manufacturing(HM),specifically additive/subtractive hybrid manufacturing(ASHM)of DED has been proposed to enhance product quality.ASHM is a capable process that combines two technologies with 3-axis or multi-axis machines.Different methods have been suggested to increase the accuracy of machines to find better quality and microstructure.In contrast,drawbacks in ASHM still exist such as limitations in existing reliable materials and poor accuracy in machine coordination to avoid collision in the multi-axes machine.It should be noted that there is no review work with focuses on both DED and hybridization of DED processes.Thus,in this review work,a unique study of DED in comparison to ASHM as well as novel techniques are discussed with the objective of showing the capabilities of each process and the benefits of using them for different applications.Finally,new gaps are discussed in ASHM to enhance the layer bonding and surface quality with the processes'effects on microstructures and performance. 展开更多
关键词 Additive manufacturing Additive/subtractive hybrid manufacturing 3D printing Hybrid manufacturing Metal alloysDirect energy deposition Machining
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High-performance martensitic stainless steel nanocomposite powder for direct energy deposition prepared by ball milling 被引量:1
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作者 Zhen Wang Shu-Rong Xu +7 位作者 Qing-Xuan Sui Jiang Wang Bo Liu Hao Wen Tian-Yi Xiao Quan Yuan Feng-Jun Zhao Jun Liu 《Rare Metals》 SCIE EI CAS CSCD 2023年第7期2419-2432,共14页
Direct energy deposition(DED)has great potential for the production of stainless steel matrix nanocomposite parts.However,the propensity of nanoparticle agglomeration leads to the difficulty in realizing homogenous di... Direct energy deposition(DED)has great potential for the production of stainless steel matrix nanocomposite parts.However,the propensity of nanoparticle agglomeration leads to the difficulty in realizing homogenous dispersion of nanoparticles in the matrix.In this study,a series of agglomeration-free nanoWC-Co-reinforced 420 stainless steel matrix nanocomposite powders with high flowability were prepared by ball milling under the optimal parameters.The effect of ball milling time on the properties of the composite powders was investigated.Excellent powder properties ensure the DED processing performance.Furthermore,the corresponding composites were fabricated by DED,and the effects of nano-WC-Co content on the properties of the composites were comprehensively investigated.The contact angles between the single pass cladding layer and the substrate change with increasing nano-WC-Co content(decrease from 127.38°to 113.07°).The different contact angles will significantly influence the quality of the multipass cladding layer.Furthermore,the addition of nanoWC-Co leads not only to further grain refinement but also to more pronounced isotropy of the micros tructure.With the increase in nano-WC-Co content,the corrosion resistance is significantly improved(62.28%lower corrosion current for 420-15 wt%nano-WC-Co than for 420). 展开更多
关键词 Steel matrix composites Direct energy deposition(DED) Ball milling time Contact angle MICROSTRUCTURE Mechanical property
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Microstructure and Mechanical Properties of an Ultrahigh-strength Titanium alloy Ti-4.5Al-5Mo-5V-6Cr-1Nb Prepared Using Laser Directed Energy Deposition and Forging:A Comparative Study 被引量:2
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作者 Junwei Yang Haibo Tang +4 位作者 Peiyuan Wei Hongwei Gao Jiawei Wang Haixin Huo Yanyan Zhu 《Chinese Journal of Mechanical Engineering(Additive Manufacturing Frontiers)》 2023年第1期55-66,共12页
The application of titanium alloys in aerospace put forward the requirement for higher strength.Additive manu-facturing is a promising method for the efficient and economical processing of titanium alloys.However,rese... The application of titanium alloys in aerospace put forward the requirement for higher strength.Additive manu-facturing is a promising method for the efficient and economical processing of titanium alloys.However,research on the additive manufacturing of ultrahigh-strength titanium alloys is still limited.The mechanisms of microseg-regation for high alloying elements and poor plasticity are still not clear.In this study,an ultrahigh-strength titanium alloy Ti-4.5Al-5Mo-5V-6Cr-1Nb(TB18)was prepared using two methods:laser direct energy deposi-tion(LDED)and forging.The LDEDed alloy contains three zones with similar grain morphologies but different microstructure.The microsegregation of the alloy is limited due to the rapid solidification and almost eliminated after the thermal cycle and solution treatment.With stress relief treatment,the LDEDed alloy exhibits anisotropic mechanical properties.After solution and aging treatments,its ultimate strength is enhanced;however,its plas-ticity is relatively lower than that of the wrought alloy with equally high strength.The excellent balance of the strength and plasticity of the wrought alloy can be ascribed to the formation of𝛼WGB and multiscale𝛼laths,which provides enlightenment for optimizing the properties of the LDEDed alloy. 展开更多
关键词 Ultrahigh-strength titanium alloy Laser directed energy deposition TB18 Microstructure Tensile properties Heat treatment
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