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Abnormal interfacial bonding mechanisms of multi-material additive-manufactured tungsten-stainless steel sandwich structure

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International Journal of Extreme Manufacturing 2022年第2期4卷 113-128页

作者： Chao Wei Heng Gu Yuchen Gu Luchao Liu Yihe Huang Dongxu Cheng Zhaoqing Li Lin Li Laser Processing Research Centre Department of MechanicalAerospace and Civil EngineeringThe University of ManchesterManchester M139PLUnited Kingdom School of Mechanical Engineering Jiangsu UniversityZhenjiangPeople’s Republic of China College of Engineering Swansea UniversitySwansea SA18ENUnited Kingdom

Tungsten(W)and stainless steel(SS)are well known for the high melting point and good corrosion resistance respectively.Bimetallic W-SS structures would offer potential applications in extreme environments.In this study,a SS→W→SS sandwich structure is fabricated via a special laser powder bed fusion(LPBF)method based on an ultrasonic-assisted powder deposition mechanism.Material characterization of the SS→W interface and W→SS interface was conducted,including microstructure,element distribution,phase distribution,and nano-hardness.A coupled modelling method,combining computational fluid dynamics modelling with discrete element method,simulated the melt pool dynamics and solidification at the material interfaces.The study shows that the interface bonding of SS→W(SS printed on W)is the combined effect of solid-state diffusion with different elemental diffusion rates and grain boundary diffusion.The keyhole mode of the melt pool at the W→SS(W printed on SS)interface makes the pre-printed SS layers repeatedly remelted,causing the liquid W to flow into the sub-surface of the pre-printed SS through the keyhole cavities realizing the bonding of the W→SS interface.The above interfacial bonding behaviours are significantly different from the previously reported bonding mechanism based on the melt pool convection during multiple material LPBF.The abnormal material interfacial bonding behaviours are reported for the first time.

关键词： multi-material additive manufacturing laser powder bed fusion interfacial bonding element diffusion keyhole mode

Selective interfacial bonding and thermal conductivity of diamond/Cu-alloy composites prepared by HPHT technique

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International Journal of Minerals,Metallurgy and Materials 2012年第4期19卷 364-371页

作者： Hui Chen Cheng-chang Jia Shang-jie Li Xian Jia Xia Yang School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Shenzhen Haimingrun Industrial Co. Ltd. Shenzhen 518126 China

Cu-based and Cu-alloy-based diamond composites were made by high-pressure-high-temperature （HPHT） sintering with the aim of maximizing the thermal conductivity of the composites. Improvements in interfacial bonding strength and thermo-physical properties of the composites were achieved using an atomized copper alloy with minor additions of Co, Cr, 13, and Ti. The thermal conductivity （TC） oh- mined exhibited as high as 688 W.m-1.K-1, but also as low as 325 W.m-1.K-l. A large variation in TC can be rationalized by the discrepancy of diamond-matrix interfacial bonding. It was found from fractography that preferential bonding between diamond and the Cu-alloy matrix occurred only on the diamond {100} faces. EDS analysis and Raman spectra suggested that selective interfacial bonding may be attributed to amorphous carbon increasing the wettability between diamond and the Cu-alloy matrix. Amorphous carbon was found to significantly affect the TC of the composite by interface modification.

关键词： metallic matrix composites diamonds copper alloys interfacial bonding thermal conductivity

Influence of interfacial bonding between Metal Droplets on Tensile Properties of 7075 Aluminum Billets by Additive Manufacturing Technique

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Journal of Materials Science & Technology 2016年第5期32卷 485-488页

作者： Hansong Zuo Hejun Li Lehua Qi Songyi Zhong State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China School of Mechanical Engineering Northwestern Polytechnical UniversityXi'an 7100721China

7075 aluminum billets were fabricated by micro droplet deposition manufacturing technique, and the influence of interracial bonding between metal droplets on the tensile properties was studied. Three sets of samples were manufactured under different temperature conditions, and their mechanical properties were compared. The results show that the temperature of the metal droplets and substrate significantly affect the tensile strength of the sample. Moreover, with proper temperature setting, the 7075 aluminum billets manufactured by micro metal droplet deposition could achieve very good mechanical properties with a tensile strength of 373 MPa and an elongation of 9.95%, which are very similar to those of an ex truded sample. Moreover, a metallurgical bonding diagram based on numerical calculations of interfacial temperature was established to predict the interfacial bonding state. In addition, the fracture morphologies of these specimens were observed. It is indicated that there was a significant transformation of failure mechanism with the improvement of metallurgical bonding, which agreed well with the numerical results.

关键词： Aluminum alloys Mechanical properties Fracture behavior interfacial bonding Additive manufacturing

Predicting and controlling interfacial microstructure of magnesium/aluminum bimetallic structures for improved interfacial bonding

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Journal of Magnesium and Alloys 2020年第3期8卷 578-586页

作者： Ziang Zhu Renhai Shi Andrew D.Klarner Alan A.Luo Yiqing Chen Materials Science and Engineering The Ohio State UniversityColumbusOHUSA Materials Science and Engineering Hefei University of TechnologyHefeiAnhuiChina Integrated Systems Engineering The Ohio State UniversityColumbusOHUSA now at M Cubed Technologies NewarkDEUSA

In this study,an overcasting process followed by a low-temperature(200°C)annealing schedule has been developed to bond magnesium to aluminum alloys.ProCAST software was used to optimize the process parameters during the overcasting process which lead to Mg/Al bimetallic structures to be successfully produced without formation of Mg-Al intermetallic phases.Detailed microstructure evolution during annealing,including the formation and growth of Al-Mg interdiffusion layer and intermetallic phases(Al12Mg17 and Al3Mg2),was experimentally observed for the first time with direct evidence,and predicted using Calculation of Phase Diagrams(CALPHAD)modeling.Maximum interfacial strength was achieved when the interdiffusion layer formed at the Mg/Al interface reached a maximum thickness the without formation of brittle intermetallic compounds.The precise diffusion modeling of the Mg/Al interface provides an efficient way to optimize and control the interfacial microstructure of Mg/Al bimetallic structures for improved interfacial bonding.

关键词： Bimetallic structure interfacial bonding CALPHAD and diffusion modeling Aluminum alloys Magnesium alloys.

Uncover the mystery of interfacial interactions in immiscible composites by spectroscopic microscopy:A case study with W-Cu

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Journal of Materials Science & Technology 2022年第31期126卷 106-115页

作者： Zhi Zhao Fawei Tang Chao Hou Xintao Huang Xiaoyan Song Faculty of Materials and Manufacturing Key Laboratory of Advanced Functional MaterialsEducation Ministry of ChinaBeijing University of TechnologyBeijing 100124China

Characterizing immiscible metallic composites with electron microscopy and X-ray spectroscopy is the classic way of obtaining their structural and physical details.Nevertheless,such a combination lacks abil-ity to tell the interfacial interactions at grain boundaries.Here we demonstrate a novel strategy to un-cover the mystery of interfacial interactions in such systems by spectroscopic microscopy.The morpho-logical and spectral data of samples were simultaneously recorded and analyzed,which reveals critical information regarding interfacial electronic modes.Taking W-Cu as a model,we experimentally quanti-fied its connectivity and unambiguously identified conditional bonding between W and Cu.Further,we chemically reconstructed the specific W-Cu boundary that possessed the strongest interactions and inves-tigated its atomic structure.The mechanism of W-Cu bonding was proposed and verified by first-principle calculations.The above methodology holds great promise to serve as a universal approach in achieving in-depth understanding of immiscible composites.

关键词： Metal-matrix composites Interface Physical properties Spectroscopic microscopy interfacial bonding

Reconfiguration and self-healing integrated Janus electrospinning nanofiber membranes for durable seawater desalination

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Nano Research 2023年第1期16卷 489-495页

作者： Huijie Liu Jiatai Gu Ye Liu Lei Yang Liming Wang Jianyong Yu Xiaohong Qin Key Laboratory of Textile Science&Technology of Ministry of Education College of TextilesDonghua UniversityShanghai 201620China State Key Laboratory for Modification of Chemical Fibers and Polymer Materials International Joint Laboratory for Advanced Fiber and Lowdimension MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai 201620China Innovation Center for Textile Science and Technology Donghua UniversityShanghai 201620China

Janus electrospinning nanofiber membranes have attracted extensive attention in the fields such as solar-driven interfacial desalination,liquid filtration,and waterproof and breathable fabrics.However,the Janus structures suffer from weak interfacial bonding and vulnerability to damage,making the durability and sustainability are highly sought after in real-word applications.Herein,we fabricate the simply reconfigurable and entirely self-healing Janus evaporator by electrospinning polypropylene glycol based polyurethane(PPG@PU)and polydimethylsiloxane based polyurethane-CNTs(PDMS@PU-CNTs)with different wettability,which are both designed based on dynamic Diels–Alder(DA)bond.The interface of the Janus membrane is stitched by the covalent bonds to directly improve the interface adhesion to 22 N·m−1,constructing an integrated evaporator,and thereby achieving a stable desalination rate of 1.34 kg·m−2·h−1 under one sun.Reversible dissociation of DA networks allows the evaporators for self-healing and reconfiguration abilities,after which the photothermal performance is maintained.This is the first work for the crosslinked self-healing polymer to be directly electrospun,achieving the improved interfacial bond and reconfiguration of entire evaporators,which presented promising new design principles and materials for interfacial solar seawater desalination.

关键词： Janus nanofiber membrane electrospinning interfacial bonding solar steam generation seawater desalination

A Comprehensive Overview on the Latest Progress in the Additive Manufacturing of Metal Matrix Composites: Potential, Challenges, and Feasible Solutions

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Acta Metallurgica Sinica(English Letters) 2021年第9期34卷 1173-1200页

作者： Mehran Dadkhah Mohammad Hossein Mosallanejad Luca Iuliano Abdollah Saboori Department of Applied Science and Technology Politecnico di TorinoCorso Duca Degli Abruzzi 2410129 TorinoItaly Department of Materials Engineering Isfahan University of Technology84156-83111 IsfahanIran Department of Management and Production Engineering Politecnico di TorinoCorso Duca Degli Abruzzi 2410129 TorinoItaly

Nowadays, as an emerging technology, additive manufacturing(AM) has received numerous attentions from researchers around the world. The method comprises layer-by-layer manufacturing of products according to the 3D CAD models of the objects. Among other things, AM is capable of producing metal matrix composites(MMCs). Hence, plenty of works in the literature are dedicated to developing different types of MMCs through AM processes. Hence, this paper provides a comprehensive overview on the latest research that has been carried out on the development of the powder-based AM manufactured MMCs from a scientific and technological viewpoint, aimed at highlighting the opportunities and challenges of this innovative manufacturing process. For instance, it is documented that AM is not only able to resolve the reinforcement/matrix bonding issues usually faced with during conventional manufacturing of MMCs, but also it is capable of producing functionally graded composites and geometrically complex objects. Furthermore, it provides the opportunity for a uniform distribution of the reinforcing phase in the metallic matrix and is able to produce composites using refractory metals thanks to the local heat source employed in the method. Despite the aforementioned advantages, there are still some challenges needing more attention from the researchers. Rapid cooling nature of the process, significantly different coe fficient of expansion of the matrix and reinforcement, processability, and the lack of suitable parameters and standards for the production of defect-free AM MMCs seem to be among the most important issues to deal with in future works.

关键词： Additive manufacturing Metal matrix composite Microstructure interfacial bonding Mechanical properties

Microstructures and mechanical behaviors of CVI-based C/C composites containing h-BN powdered additives

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Journal of Materials Science & Technology 2019年第12期35卷 2824-2831页

作者： Peng Xiao Zhichao Li Zeyan Liu Zhuan Li Bengu Zhang Jinwei Li Yang Li National Key Laboratory of Science and Technology for National Defence on High-strength Structural Materials Central South UniversityChangsha 410083China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083China

Hexagonal boron nitride(h-BN) powders were introduced into carbon fiber preform by powder addition and subsequent combined with chemical vapor infiltration(CVI) for densification to prepare carbon fiber reinforced/carbon and boron nitride dual matrix composites(C/C-BN). Microstructures and mechanical properties of C/C composites with three different volume contents of h-BN powders were investigated in comparison to pure C/C composites. Results indicated that the introduction of h-BN powders into C/C composites significantly reduced the size of Py C and the anisotropy of thermal contraction in matrix,leading to a gradual disappearance of ring defects as the h-BN content increased. In addition, an enhanced interfacial bonding between fiber and matrix obtained due to higher-textured Py C and rougher fiber surface. Thereby, the flexural strengths and modulus of as-prepared composites decreased firstly and then increased, while the impact toughness presented a decreasing tendency as the content of BN powders increased. Furthermore, with the increasing of h-BN content, anisotropies of compressive properties were weakened, and the compressive strength of C/C-BN composites were always higher than that of pure C/C composit. However, when C/C composites modified by 13.5 vol% content of h-BN, excessive loose BN aggregates appeared in C/C-BN composites, leading to a relatively slight reduction of compressive strength.

关键词： C/C composites h-BN Pyrolytic carbon interfacial bonding Mechanical properties

Mechanical characterization of functional graphene nanoplatelets coated natural and synthetic fiber yarns using polymeric binders

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International Journal of Smart and Nano Materials 2020年第1期11卷 78-91页

作者： Velram Balaji Mohan Debes Bhattacharyya Plastics Centre of Excellence&Centre for Advanced Composite Materials Department of Mechanical EngineeringThe University of AucklandAucklandNew Zealand

Fabrication of electrically conductive yarns(glass,flax and polypropylene fibers)coated with graphene nanoparticles(GNP)were characterized for their mechanical properties and compared with their electrical properties.The composites were produced with the use of polymeric binders(epoxy resin and thermoplastic starch)and two different dipcoating methodologies were developed to create the coating layers.Technique-1 involved coating of binder and then GNP layer whereas Technique-2 had a mixture of binder and GNP in the predetermined ratio,which was coated on the yarns.The mechanism of adhesion varies or influences on a number of factors such as the nature of the fiber surface,coating method and effective binder.Tensile properties of the yarns were measured by an appropriate standard,and the highest tensile strength was noticed with epoxy-based glass fiber samples as 222 MPa followed by flax fiber samples as 206 MPa.The composites of starch-based showed poor mechanical performance compared to those of epoxy ones.This was due to poor adhesion between the surface and starch layer(interphase)where the Van der Wall’s force was quite low.Electrical conductivity,glass fiber yarns with epoxy binder were identified to have the highest electrical conductivity of 0.1 S.cm−1 among other samples.

关键词： Coating fiber yarn composites conductive yarns mechanical properties interfacial bonding microstructure