This paper provides a comprehensive review of research progress in particle-reinforced Mg matrix composites prepared via powder metallurgy.The article discusses different strategies,such as micro-sized,nano-sized part...This paper provides a comprehensive review of research progress in particle-reinforced Mg matrix composites prepared via powder metallurgy.The article discusses different strategies,such as micro-sized,nano-sized particles,and multi-particle hybridization,which has been employed to enhance the performance of the composites.In addition,a range of preparation techniques that optimize the dispersion of the reinforcing particles are summarized.The paper also highlights how the different configurations between the reinforcements and matrix alloy impact the composites’performance.Finally,the article outlines the prospects of particles reinforced Mg matrix composites fabricated via powder metallurgy and recommends modification methods that could be explored to further develop these materials for various applications.展开更多
Magnesium matrix composites have garnered significant attention in recent years owing to their exceptional lightweight properties and notable potential in various engineering applications.The interface generally acts ...Magnesium matrix composites have garnered significant attention in recent years owing to their exceptional lightweight properties and notable potential in various engineering applications.The interface generally acts as a“bridge”between the matrix and reinforcement,playing crucial roles in critical processes such as load transfer,failure behavior,and carrier transport.A deep understanding of the interfacial structures,properties,and effects holds paramount significance in the study of composites.This paper presents a comprehensive review of prior researches related to the interface of Mg matrix composites.Firstly,the different interfacial structures and interaction mechanisms encompassing mechanical,physical,and chemical bonding are introduced.Subsequently,the interfacial mechanical properties and their influence on the overall properties are discussed.Finally,the paper addresses diverse interface modification methods including matrix alloying and reinforcement surface treatment.展开更多
Mg matrix composites(Mg MCs)with enhanced mechanical and functional properties,as well as improved elastic modulus,have aroused rising attention from the aerospace,new energy vehicles,and consumer electronics industri...Mg matrix composites(Mg MCs)with enhanced mechanical and functional properties,as well as improved elastic modulus,have aroused rising attention from the aerospace,new energy vehicles,and consumer electronics industries.The suitability of the fabrication process is crucial for achieving uniform dispersion of various reinforcing materials within the Mg alloy matrix and for forming strong interfacial bonding.This ensures that the produced Mg MCs meet the requirements for fabricating various components with different demands for size and properties.This paper comprehensively reviews the present fabrication methods for MgMCs in four categories:stir casting,external addition methods,in-situ synthesis methods and novel fabrication methods.It comprehensively focuses on the fabrication principles,process characteristics and key parameters optimization of each technology.Through in-depth analysis,their advantages,limitations and applications are evaluated.Meanwhile,the latest research achievements in microstructure control and mechanical performance optimization are explored.Eventually,the development directions of the fabrication methods for MgMCs in the future are also discussed.展开更多
A novel Mg^(-1)0Li-3Al(wt.%,LA103)matrix composite reinforced by ex situ micron TiB_(2) particles was developed in the present study.The ball milling and cold pressing pretreatment of the reinforcements made it feasib...A novel Mg^(-1)0Li-3Al(wt.%,LA103)matrix composite reinforced by ex situ micron TiB_(2) particles was developed in the present study.The ball milling and cold pressing pretreatment of the reinforcements made it feasible to prepare this material under stir casting conditions with good dispersion.The microstructure and mechanical properties of the composites prepared by different pretreatment methods were analyzed in detail.The TiB_(2) particles in the Al-TiB_(2)/LA103 composite using the pretreatment process were uniformly distributed in the microstructure due to the formation of highly wettable core-shell units in the melt.Compared with the matrix alloys,the Al-TiB_(2)/LA103 composite exhibited effective strength and elastic modulus improvements while maintaining acceptable elongation.The strengthening effect in the composites was mainly attributed to the strong grain refining effect of TiB2.This work shows a balance of high specific modulus(36.1 GPa·cm^(3)·g^(-1))and elongation(8.4%)with the conventional stir casting path,which is of considerable application value.展开更多
In this article,in-situ scanning electron microscope characterization of the tensile properties of TiB/Ti-2Al-6Sn titanium matrix composite(TMC)was conducted before and after electroshocking treatment(EST).After EST,t...In this article,in-situ scanning electron microscope characterization of the tensile properties of TiB/Ti-2Al-6Sn titanium matrix composite(TMC)was conducted before and after electroshocking treatment(EST).After EST,the tensile strength increased by 113.2 MPa.The effect of EST on the tensile strength and fracture behavior of TiB was investigated using in-situ characterization of the fracture morphology and crack propagation path of the matrix and TiB.Before EST,TiB fracture introduced cracks that extended into the matrix,resulting in material failure.After EST,the refined TiB improved the bearing capacity of the matrix,thereby improving TMC strength.Moreover,after EST,the cracks were introduced into the matrix,and resulting the fracture of matrix first.With an increase in the external load,cracks in the matrix were observed to propagate to TiB,and the refined TiB was fractured,detached,and pulled out,resulting in the formation of pores.Analyzing the propagation path of the main crack after EST showed that the deflection angle of the main crack increased.The micro structure of the fracture surface indicated that the fracture of the matrix was plastic,whereas that of TiB was brittle.After EST,the size and area of the dimples increased,confirming the increase in plasticity.The results revealed that the comprehensive mechanical properties of TiB/Ti-2Al-6Sn improved after EST.Hence,EST is an efficient method for tailoring the micro structures and mechanical properties of TMCs.展开更多
Realizing the uniform dispersion of nanocarbons such as carbon nanotube and graphene in metals, is an essential prerequisite to fully exhibit their enhancement effect in mechanical, thermal, and electrical properties ...Realizing the uniform dispersion of nanocarbons such as carbon nanotube and graphene in metals, is an essential prerequisite to fully exhibit their enhancement effect in mechanical, thermal, and electrical properties of metal matrix composites(MMCs). In this work, we propose an effective method to achieve uniform distribution of nanocarbons in various metal flakes through a slurry-based method. It relies on the electrostatic interactions between the negatively charged nanocarbons and the positively charged metal flakes when mixed in slurry. For case study, flake metal powders(Al, Mg, Ti,Fe, and Cu) were positively charged in aqueous suspension by spontaneous ionization or cationic surface modification. While nanocarbons, given examples as carboxylic multi-walled carbon nanotubes, pristine single-walled carbon nanotube, and carbon nanotube–graphene oxide hybrid were negatively charged by the ionization of oxygen-containing functional groups or anionic surfactant. It was found that through the electrostatic interaction mechanism, all kinds of nanocarbons can be spontaneously and efficiently adsorbed onto the surface of various metal flakes. The development of such a versatile method would provide us great opportunities to fabricate advanced MMCs with appealing properties.展开更多
Powder metallurgy （PM） is one of the most applied processes in the fabrication of metal matrix composites （MMCs）. Recently, a novel PM strategy called flake PM was developed to fabricate MMCs with nano-laminated o...Powder metallurgy （PM） is one of the most applied processes in the fabrication of metal matrix composites （MMCs）. Recently, a novel PM strategy called flake PM was developed to fabricate MMCs with nano-laminated or hierarchical architectures. The name ＂flake PM＂ was derived from the use of flake metal powders, which could benefit the uniform dispersion of reinforcements in the metal matrices and thus result in balanced strength and ductility. Flake PM has been proved to be successful in the dispersion of nano aluminum oxides, carbon nanotubes, graphene nano-sheets, and microsized B4C particles in aluminum or copper matrix. This paper reviews the technique and mechanism developments of flake PM in previous studies, and foresees the future develop of this new fabricating method.展开更多
In-situ TiC and remained multi-walled carbon nanotubes（MWCNTs） reinforced Ti composites were synthesized using vacuum hot-press sintering and hot rolling. The effect of weight fraction of MWCNTs on microstructural e...In-situ TiC and remained multi-walled carbon nanotubes（MWCNTs） reinforced Ti composites were synthesized using vacuum hot-press sintering and hot rolling. The effect of weight fraction of MWCNTs on microstructural evolution and mechanical properties of the Ti composites was investigated. The results indicated that both proportion and particle size of TiC increased in proportion to MWCNTs content, which resulted in different matrix microstructure, and the grains were obviously refined after rolling deformation. The hardness tests indicated that MWCNTs addition could make the composites harden, and 18.4%improvement in hardness was obtained after hot rolling. The significant improvement in both strength and hardness could be attributed to grain refinement, solid solution strengthening of carbon and dispersion strengthening of TiC particles and remained MWCNTs. A good combination of strength and ductility were achieved in Ti–1 wt% MWCNTs composites, which were in accordance with the uniform distribution of smaller-sized TiC particles in Ti matrix.展开更多
Non-interlayer liquid phase diffusion welding (China Patent) and laser welding methods for aluminum matrix composite are mainly described in this paper. In the non-interlayer liquid phase diffusion welding, the key pr...Non-interlayer liquid phase diffusion welding (China Patent) and laser welding methods for aluminum matrix composite are mainly described in this paper. In the non-interlayer liquid phase diffusion welding, the key processing parameters affecting the strength of joint is welding temperature. When temperature rises beyond solidus temperature, the bonded line vanishes. The strength of joint reaches the maximum and becomes constant when welding temperature is close to liquid phase temperature. Oxide film in the interface is no longer detected by SEM in the welded joint. With this kind of technique, particle reinforced aluminum matrix composite Al2 O3p/6061Al is welded successfully, and the joint strength is about 80% of the strength of composite (as-casted). In the laser welding, results indicate that because of the huge specific surface area of the reinforcement, the interfacial reaction between the matrix and the reinforcement is restrained intensively at certain laser power and pulsed laser beam. The laser pulse frequency directly affects the reinforcement segregation and the reinforcement distribution in the weld, so that the weldability of the composite could be improved by increasing the laser pulse frequency. The maximum strength of the weld can reach 70% of the strength of the parent.展开更多
Metal matrix composites(MMCs)incorporate a reinforcing or functional secondary phase into a metal matrix to achieve specific properties.Of the parameters which may affect the mechanical behavior of MMCs,the structure ...Metal matrix composites(MMCs)incorporate a reinforcing or functional secondary phase into a metal matrix to achieve specific properties.Of the parameters which may affect the mechanical behavior of MMCs,the structure and properties of the reinforcement/matrix interface play a crucial role.This article reviews recent developments in measuring the interfacial properties in advanced MMCs,with an emphasis on the use of micro-/nano-mechanical testing approaches.It is shown that,with the novel in situ and ex situ experimental capability,researchers can now obtain some of the critical interfacial properties as well as the effects of reinforcement/matrix interfaces on the composites’deformation and failure mechanisms that were unattainable previously by conventional methodologies.Moreover,the micro-/nano-mechanical testing platform allows for both fundamental and applied research on the composites’mechanical performance under service conditions,which is considered a promising and emerging research direction.展开更多
Considerable studies on processed pure titanium and titanium alloys have proved the possibility of prop-erty anisotropy induced by crystallographic textures,but limited information is available for the intrinsic coupl...Considerable studies on processed pure titanium and titanium alloys have proved the possibility of prop-erty anisotropy induced by crystallographic textures,but limited information is available for the intrinsic coupling of matrix and reinforcement textures and their synergistic effect on property anisotropy in tita-nium matrix composite(TMCs).In the present work,an advanced EBSD/EDS coupling method was used to investigate the formation mechanism of primaryαand secondaryαtextures in the matrix alloy.It is revealed for the first time that the reinforcement TiB_(w)displays a{100}<010>texture after hot rolling and has little effect on the matrix texture component but weakens texture intensity.Significant anisotropies in the tensile strength and ductility can be all noted at room and high-temperatures,which is the syn-ergistic effect of the matrix texture and the aligned TiB_(w).The mean Schmid factor of each slip system was calculated to evaluate the influence of matrix texture on the minimum active stress of slip deforma-tion in the different tensile directions.The analysis shows that the strong T-type matrix texture results in higher strength but lower ductility when loaded in the transverse direction.Moreover,a generalized shear-lag model was modified to quantitatively evaluate the strengthening contribution of aligned TiB_(w),which decreases with increasing off-axis angle and test temperature.A new parameter,defined as the critical aspect ratio of the off-axis whisker,was proposed to rationalize why the TiB_(w) failure mechanism converts from TiB_(w) fracture to TiB_(w)/matrix interfacial debonding with increasing off-axis angle and test temperature.展开更多
This work dealt with the damping performance and its underlying mechanism in SiC nanoparticles reinforced AZ91D composite(SiC_(np)/AZ91D)processed by cyclic extrusion and compression(CEC).It was found that the CEC pro...This work dealt with the damping performance and its underlying mechanism in SiC nanoparticles reinforced AZ91D composite(SiC_(np)/AZ91D)processed by cyclic extrusion and compression(CEC).It was found that the CEC process significantly affects the damping performance of the composite due to alterations in the density of dislocations and grain boundaries in the matrix alloy.Although there would be dynamic precipitation of the Mg17Al12 phase during processing which increases the phase interface and limits the mobility of dislocations and grain boundaries.The results also showed that the damping capacity of 1%SiC_(np)/AZ91D composite continuously decreases with adding CEC pass number and it consistently increases with rising the applied temperature.Considering the first derivative of the tanδ-T curve,the dominant damping mechanism based on test temperature can be divided into three regions.These three regions are as follows(i)dislocation vibration of the weak pinning points(≤T_(cr)),(ii)dislocation vibration of the strong pinning points(T_(cr)∼T_(V)),and(iii)grain boundary/interface sliding(≥T_(V))展开更多
In this paper, a new method for welding SiCp/101A was put forward. It is LPI (liquid-phase-impacting) diffusionwelding. Through LPI diffusion welding SiCp/101A aluminum, the effect of welding parameters on the weldedj...In this paper, a new method for welding SiCp/101A was put forward. It is LPI (liquid-phase-impacting) diffusionwelding. Through LPI diffusion welding SiCp/101A aluminum, the effect of welding parameters on the weldedjoint property was investigated, and the optimal welding parameters were brought forward at the same time. Themicrostructure of joint was analyzed by means of optical-microscope, scanning electron microscope in order to studythe relationship between the macro-properties of joint and the microstructure. The results show that LPI diffusionwelding could be used for welding aluminum matrix composites SiCp/101A successfully.展开更多
Magnesium alloy reinforced with 8% TiC(mass fraction) is in-situ synthesized using remelting and dilution technique. Damping capacity of AZ91 alloy and magnesium matrix composites was examined using Mark IV dynamic me...Magnesium alloy reinforced with 8% TiC(mass fraction) is in-situ synthesized using remelting and dilution technique. Damping capacity of AZ91 alloy and magnesium matrix composites was examined using Mark IV dynamic mechanical thermal analyzer. The results reveal that the damping capacity of materials is independent of frequency, but dependent on strain. Damping capacity of materials increase when testing strain enhances, and there is strain peak at damping-strain curve of materials. There are two temperature peaks at damping-temperature curve of magnesium matrix composites under 140℃ and 250℃ respectively. The damping mechanism is explained by dislocation motion, interface slip and grain boundary slip.展开更多
The liquid-phase-impacting (LPI) diffusion welding mechanism and microstructure of welded joint of aluminum matrixcomposite SiCp/101A have been studied. It shows that by LPl diffusion welding, the interface state betw...The liquid-phase-impacting (LPI) diffusion welding mechanism and microstructure of welded joint of aluminum matrixcomposite SiCp/101A have been studied. It shows that by LPl diffusion welding, the interface state between SiCparticle and matrix is prominent, the harmful microstructure or brittle phase can be restrained from the welded joint.Moreover, the density of dislocation in the matrix near the interface and in the matrix are all so higher than that ofparent composite, the dislocation entwists each other intensively resulted in welding the composite successfully.展开更多
Through the vacuum diffusion bonding for SiCp/ZLl01 aluminum matrix composite, the influence of bonding parameters on the joint properties was reported, with the aim to obtain optimal bonding parameters. The microstru...Through the vacuum diffusion bonding for SiCp/ZLl01 aluminum matrix composite, the influence of bonding parameters on the joint properties was reported, with the aim to obtain optimal bonding parameters. The microstructureof joints was analyzed by means of optical microscope and scanning electron microscope in order to study the relationship between the macro-properties of joints and the microstructures. It was found that diffusion bonding couldbe used for bonding aluminum matrix composites successfully. Meanwhile, the properties of the matrix and the jointwere all affected by some defects such as the reinforcement aggregation in aluminum matrix composites made bystirring casting.展开更多
TiC/ZA43 composites were fabricated by XD TM and stirring casting techniques. The tribology properties of the unreinforced ZA43 alloy and the composites were studied by using a block on ring apparatus. Experimental re...TiC/ZA43 composites were fabricated by XD TM and stirring casting techniques. The tribology properties of the unreinforced ZA43 alloy and the composites were studied by using a block on ring apparatus. Experimental results show that the incorporation of TiC particles improves the microstructure of ZA43 matrix alloy. The coefficient of friction μ and the width of worn groove decrease with the increase of TiC volume fraction φ (TiC). The width of worn groove and μ of the composite during wear testing increase with increasing the applied load. Metallographic examinations reveal that unreinforced ZA43 alloy has deep ploughing grooves with obvious adhesion phenomenon, whereas TiC/ZA43 composites have smooth worn surface. Delamination formation is related to the fatigue cracks and the shear cracks on the surface. [展开更多
SiCp/Gr/2024Al metal matrix composites were processed by squeeze casting technology. The microstructure of composites was observed by SEM and TEM, and the effects of graphite particulates and SiC particulates on the d...SiCp/Gr/2024Al metal matrix composites were processed by squeeze casting technology. The microstructure of composites was observed by SEM and TEM, and the effects of graphite particulates and SiC particulates on the damping behaviors of composites were also investigated. The results show that the microstructure of composites was dense and homogeneous, without any interfacial reactivity among reinforcement/matrix interfaces. Compared with the damping capacity of 2024A1, the damping capacity of composites was enhanced significantly by addition of SiC or graphite particulates. The main damping mechanisms of SiCp/Al composites were ascribed to the dislocation damping, and those of SiCp/Gr/2024Al were attributed to the intrinsic damping and interface damping.展开更多
基金supports of the National Natural Science Foundation of China (Nos.U2241231 and 51631006).
文摘This paper provides a comprehensive review of research progress in particle-reinforced Mg matrix composites prepared via powder metallurgy.The article discusses different strategies,such as micro-sized,nano-sized particles,and multi-particle hybridization,which has been employed to enhance the performance of the composites.In addition,a range of preparation techniques that optimize the dispersion of the reinforcing particles are summarized.The paper also highlights how the different configurations between the reinforcements and matrix alloy impact the composites’performance.Finally,the article outlines the prospects of particles reinforced Mg matrix composites fabricated via powder metallurgy and recommends modification methods that could be explored to further develop these materials for various applications.
基金supported by the financial support from the National Key Research and Development Program of China(No.2022YFB3708400)National Natural Science Foundation of China(grant No.52305158)+1 种基金Science Innovation Foundation of Shanghai Academy of Spaceflight Technology(No.USCAST2021-18)Funding from Aero Engine 484 Cooporation of China(ZZCX-2022-020).
文摘Magnesium matrix composites have garnered significant attention in recent years owing to their exceptional lightweight properties and notable potential in various engineering applications.The interface generally acts as a“bridge”between the matrix and reinforcement,playing crucial roles in critical processes such as load transfer,failure behavior,and carrier transport.A deep understanding of the interfacial structures,properties,and effects holds paramount significance in the study of composites.This paper presents a comprehensive review of prior researches related to the interface of Mg matrix composites.Firstly,the different interfacial structures and interaction mechanisms encompassing mechanical,physical,and chemical bonding are introduced.Subsequently,the interfacial mechanical properties and their influence on the overall properties are discussed.Finally,the paper addresses diverse interface modification methods including matrix alloying and reinforcement surface treatment.
基金supported by the financial support from the National Natural Science Foundation of China(grant Nos.52471012,52425101 and 52305158)Science Innovation Foundation of Shanghai Academy of Spaceflight Technology(No.USCAST2021–18)Young Elite Scientists Sponsorship Program by China Association for Science and Technology(No.YESS20220350)。
文摘Mg matrix composites(Mg MCs)with enhanced mechanical and functional properties,as well as improved elastic modulus,have aroused rising attention from the aerospace,new energy vehicles,and consumer electronics industries.The suitability of the fabrication process is crucial for achieving uniform dispersion of various reinforcing materials within the Mg alloy matrix and for forming strong interfacial bonding.This ensures that the produced Mg MCs meet the requirements for fabricating various components with different demands for size and properties.This paper comprehensively reviews the present fabrication methods for MgMCs in four categories:stir casting,external addition methods,in-situ synthesis methods and novel fabrication methods.It comprehensively focuses on the fabrication principles,process characteristics and key parameters optimization of each technology.Through in-depth analysis,their advantages,limitations and applications are evaluated.Meanwhile,the latest research achievements in microstructure control and mechanical performance optimization are explored.Eventually,the development directions of the fabrication methods for MgMCs in the future are also discussed.
基金supported by the National Natural Science Foundation of China(Nos.51821001 and U2037601)Major Scientific and Technological Inno-vation Projects in Luoyang(No.2201029A)+1 种基金Foundation Strengthening Plan Technical Field Fund(No.2021-JJ-0112)Shanghai Jiao Tong University Student Innovation Prac-tice Program(No.IPP24076).
文摘A novel Mg^(-1)0Li-3Al(wt.%,LA103)matrix composite reinforced by ex situ micron TiB_(2) particles was developed in the present study.The ball milling and cold pressing pretreatment of the reinforcements made it feasible to prepare this material under stir casting conditions with good dispersion.The microstructure and mechanical properties of the composites prepared by different pretreatment methods were analyzed in detail.The TiB_(2) particles in the Al-TiB_(2)/LA103 composite using the pretreatment process were uniformly distributed in the microstructure due to the formation of highly wettable core-shell units in the melt.Compared with the matrix alloys,the Al-TiB_(2)/LA103 composite exhibited effective strength and elastic modulus improvements while maintaining acceptable elongation.The strengthening effect in the composites was mainly attributed to the strong grain refining effect of TiB2.This work shows a balance of high specific modulus(36.1 GPa·cm^(3)·g^(-1))and elongation(8.4%)with the conventional stir casting path,which is of considerable application value.
基金financially supported by the National Natural Science Foundation of China(No.52271135)the Major Research Plan of the National Natural Science Foundation of China(No.92266102)+5 种基金the Natural Science Foundation of Hubei Province(No.2022CFB492)the Knowledge Innovation Program of Wuhan-Basic Research(No.2022010801010174)the Application Foundation Frontier Project of Wuhan(No.2020010601012171)"Chu Tian Scholar"Project of Hubei Province(No.CTXZ2017-05)the Overseas Expertise Introduction Project for Discipline Innovation(No.B17034)the Innovative Research Team Development Program of Ministry of Education of China(No.IRT_17R83)。
文摘In this article,in-situ scanning electron microscope characterization of the tensile properties of TiB/Ti-2Al-6Sn titanium matrix composite(TMC)was conducted before and after electroshocking treatment(EST).After EST,the tensile strength increased by 113.2 MPa.The effect of EST on the tensile strength and fracture behavior of TiB was investigated using in-situ characterization of the fracture morphology and crack propagation path of the matrix and TiB.Before EST,TiB fracture introduced cracks that extended into the matrix,resulting in material failure.After EST,the refined TiB improved the bearing capacity of the matrix,thereby improving TMC strength.Moreover,after EST,the cracks were introduced into the matrix,and resulting the fracture of matrix first.With an increase in the external load,cracks in the matrix were observed to propagate to TiB,and the refined TiB was fractured,detached,and pulled out,resulting in the formation of pores.Analyzing the propagation path of the main crack after EST showed that the deflection angle of the main crack increased.The micro structure of the fracture surface indicated that the fracture of the matrix was plastic,whereas that of TiB was brittle.After EST,the size and area of the dimples increased,confirming the increase in plasticity.The results revealed that the comprehensive mechanical properties of TiB/Ti-2Al-6Sn improved after EST.Hence,EST is an efficient method for tailoring the micro structures and mechanical properties of TMCs.
基金the financial support of the National Basic Research Program(973 Program)(No.2012CB619600)the National Natural Science Foundation(Nos.51131004,51071100,51001071,51511130038,51501111,51471190)+1 种基金the National High-Tech R&D Program(863 Program)(No.2012AA030311)the research grant(Nos.14DZ2261200,15JC1402100,13PJ1404000,14520710100)from Shanghai government
文摘Realizing the uniform dispersion of nanocarbons such as carbon nanotube and graphene in metals, is an essential prerequisite to fully exhibit their enhancement effect in mechanical, thermal, and electrical properties of metal matrix composites(MMCs). In this work, we propose an effective method to achieve uniform distribution of nanocarbons in various metal flakes through a slurry-based method. It relies on the electrostatic interactions between the negatively charged nanocarbons and the positively charged metal flakes when mixed in slurry. For case study, flake metal powders(Al, Mg, Ti,Fe, and Cu) were positively charged in aqueous suspension by spontaneous ionization or cationic surface modification. While nanocarbons, given examples as carboxylic multi-walled carbon nanotubes, pristine single-walled carbon nanotube, and carbon nanotube–graphene oxide hybrid were negatively charged by the ionization of oxygen-containing functional groups or anionic surfactant. It was found that through the electrostatic interaction mechanism, all kinds of nanocarbons can be spontaneously and efficiently adsorbed onto the surface of various metal flakes. The development of such a versatile method would provide us great opportunities to fabricate advanced MMCs with appealing properties.
基金financially supported by the National Basic Research Program of China (No.2012CB619600)the National Natural Science Foundation of China (Nos.51131004,51071100 and 51001071)+1 种基金the National High Technology Research and Development Program of China (No.2012AA030311)Shanghai Science and Technology Committee (No.11JC1405500)
文摘Powder metallurgy （PM） is one of the most applied processes in the fabrication of metal matrix composites （MMCs）. Recently, a novel PM strategy called flake PM was developed to fabricate MMCs with nano-laminated or hierarchical architectures. The name ＂flake PM＂ was derived from the use of flake metal powders, which could benefit the uniform dispersion of reinforcements in the metal matrices and thus result in balanced strength and ductility. Flake PM has been proved to be successful in the dispersion of nano aluminum oxides, carbon nanotubes, graphene nano-sheets, and microsized B4C particles in aluminum or copper matrix. This paper reviews the technique and mechanism developments of flake PM in previous studies, and foresees the future develop of this new fabricating method.
基金supported financially by the National Natural Science Foundation of China (Nos. 51371114, 51501112 and U1602274)the Fund of the State Key Laboratory of Solidification Processing in NWPU (No. SKLSP201620)+2 种基金the Shanghai Academy of Spaceflight-Joint Research Centre of Shanghai Jiao Tong University advanced aerospace technology (No. US-CAST2012-14)the National Engineering and Research Center for Commercial Aircraft Manufacturing (No. SAMC14-JS-15-047)the 111 Project (No. B16032)
文摘In-situ TiC and remained multi-walled carbon nanotubes（MWCNTs） reinforced Ti composites were synthesized using vacuum hot-press sintering and hot rolling. The effect of weight fraction of MWCNTs on microstructural evolution and mechanical properties of the Ti composites was investigated. The results indicated that both proportion and particle size of TiC increased in proportion to MWCNTs content, which resulted in different matrix microstructure, and the grains were obviously refined after rolling deformation. The hardness tests indicated that MWCNTs addition could make the composites harden, and 18.4%improvement in hardness was obtained after hot rolling. The significant improvement in both strength and hardness could be attributed to grain refinement, solid solution strengthening of carbon and dispersion strengthening of TiC particles and remained MWCNTs. A good combination of strength and ductility were achieved in Ti–1 wt% MWCNTs composites, which were in accordance with the uniform distribution of smaller-sized TiC particles in Ti matrix.
基金supported by the National Natural Science Foundation of China(No.50171025)open project of foundation of National Key Laboratory of Metal Matrix Composite,Shanghai Jiaotong University
文摘Non-interlayer liquid phase diffusion welding (China Patent) and laser welding methods for aluminum matrix composite are mainly described in this paper. In the non-interlayer liquid phase diffusion welding, the key processing parameters affecting the strength of joint is welding temperature. When temperature rises beyond solidus temperature, the bonded line vanishes. The strength of joint reaches the maximum and becomes constant when welding temperature is close to liquid phase temperature. Oxide film in the interface is no longer detected by SEM in the welded joint. With this kind of technique, particle reinforced aluminum matrix composite Al2 O3p/6061Al is welded successfully, and the joint strength is about 80% of the strength of composite (as-casted). In the laser welding, results indicate that because of the huge specific surface area of the reinforcement, the interfacial reaction between the matrix and the reinforcement is restrained intensively at certain laser power and pulsed laser beam. The laser pulse frequency directly affects the reinforcement segregation and the reinforcement distribution in the weld, so that the weldability of the composite could be improved by increasing the laser pulse frequency. The maximum strength of the weld can reach 70% of the strength of the parent.
基金supported by financial support from the National Key Research and Development Program of China(No.2017YFB0703103,2016YFE0130200)the Natural Science Foundation of China(Nos.51771111)the Science&Technology Committee of Shanghai Municipality(No.17520712400).
文摘Metal matrix composites(MMCs)incorporate a reinforcing or functional secondary phase into a metal matrix to achieve specific properties.Of the parameters which may affect the mechanical behavior of MMCs,the structure and properties of the reinforcement/matrix interface play a crucial role.This article reviews recent developments in measuring the interfacial properties in advanced MMCs,with an emphasis on the use of micro-/nano-mechanical testing approaches.It is shown that,with the novel in situ and ex situ experimental capability,researchers can now obtain some of the critical interfacial properties as well as the effects of reinforcement/matrix interfaces on the composites’deformation and failure mechanisms that were unattainable previously by conventional methodologies.Moreover,the micro-/nano-mechanical testing platform allows for both fundamental and applied research on the composites’mechanical performance under service conditions,which is considered a promising and emerging research direction.
基金financially supported by the National Natural Scienc e Foundation of China(Nos.U1602274,51875349,51871150 and 51821001)the National Key R&D Program of China(No.2018YFB1106403)+2 种基金the Medical Intersection Project of Shanghai Jiao Tong University(Nos.ZH2018QNA22 and YG2017QN28)the 111 Project(No.B16032)the Laboratory Innovative Research Pro-gram of Shanghai Jiao Tong University(No.17SJ-14).
文摘Considerable studies on processed pure titanium and titanium alloys have proved the possibility of prop-erty anisotropy induced by crystallographic textures,but limited information is available for the intrinsic coupling of matrix and reinforcement textures and their synergistic effect on property anisotropy in tita-nium matrix composite(TMCs).In the present work,an advanced EBSD/EDS coupling method was used to investigate the formation mechanism of primaryαand secondaryαtextures in the matrix alloy.It is revealed for the first time that the reinforcement TiB_(w)displays a{100}<010>texture after hot rolling and has little effect on the matrix texture component but weakens texture intensity.Significant anisotropies in the tensile strength and ductility can be all noted at room and high-temperatures,which is the syn-ergistic effect of the matrix texture and the aligned TiB_(w).The mean Schmid factor of each slip system was calculated to evaluate the influence of matrix texture on the minimum active stress of slip deforma-tion in the different tensile directions.The analysis shows that the strong T-type matrix texture results in higher strength but lower ductility when loaded in the transverse direction.Moreover,a generalized shear-lag model was modified to quantitatively evaluate the strengthening contribution of aligned TiB_(w),which decreases with increasing off-axis angle and test temperature.A new parameter,defined as the critical aspect ratio of the off-axis whisker,was proposed to rationalize why the TiB_(w) failure mechanism converts from TiB_(w) fracture to TiB_(w)/matrix interfacial debonding with increasing off-axis angle and test temperature.
基金This work was supported by the National Natural Science Foundation of China(Grant Numbers of U1902220,51674166,51374145,51074106,50674067)the National Key Research and Development Program of China(Grant Number 2016YFB0301001).
文摘This work dealt with the damping performance and its underlying mechanism in SiC nanoparticles reinforced AZ91D composite(SiC_(np)/AZ91D)processed by cyclic extrusion and compression(CEC).It was found that the CEC process significantly affects the damping performance of the composite due to alterations in the density of dislocations and grain boundaries in the matrix alloy.Although there would be dynamic precipitation of the Mg17Al12 phase during processing which increases the phase interface and limits the mobility of dislocations and grain boundaries.The results also showed that the damping capacity of 1%SiC_(np)/AZ91D composite continuously decreases with adding CEC pass number and it consistently increases with rising the applied temperature.Considering the first derivative of the tanδ-T curve,the dominant damping mechanism based on test temperature can be divided into three regions.These three regions are as follows(i)dislocation vibration of the weak pinning points(≤T_(cr)),(ii)dislocation vibration of the strong pinning points(T_(cr)∼T_(V)),and(iii)grain boundary/interface sliding(≥T_(V))
基金This work was supported by the National Natural Science Foundation of China (No. 90205035, 50171025).
文摘In this paper, a new method for welding SiCp/101A was put forward. It is LPI (liquid-phase-impacting) diffusionwelding. Through LPI diffusion welding SiCp/101A aluminum, the effect of welding parameters on the weldedjoint property was investigated, and the optimal welding parameters were brought forward at the same time. Themicrostructure of joint was analyzed by means of optical-microscope, scanning electron microscope in order to studythe relationship between the macro-properties of joint and the microstructure. The results show that LPI diffusionwelding could be used for welding aluminum matrix composites SiCp/101A successfully.
文摘Magnesium alloy reinforced with 8% TiC(mass fraction) is in-situ synthesized using remelting and dilution technique. Damping capacity of AZ91 alloy and magnesium matrix composites was examined using Mark IV dynamic mechanical thermal analyzer. The results reveal that the damping capacity of materials is independent of frequency, but dependent on strain. Damping capacity of materials increase when testing strain enhances, and there is strain peak at damping-strain curve of materials. There are two temperature peaks at damping-temperature curve of magnesium matrix composites under 140℃ and 250℃ respectively. The damping mechanism is explained by dislocation motion, interface slip and grain boundary slip.
基金This work was supported by the National Natural Science Foundation of China under grant No. 50171025.
文摘The liquid-phase-impacting (LPI) diffusion welding mechanism and microstructure of welded joint of aluminum matrixcomposite SiCp/101A have been studied. It shows that by LPl diffusion welding, the interface state between SiCparticle and matrix is prominent, the harmful microstructure or brittle phase can be restrained from the welded joint.Moreover, the density of dislocation in the matrix near the interface and in the matrix are all so higher than that ofparent composite, the dislocation entwists each other intensively resulted in welding the composite successfully.
基金This work was supported by the National Natural Science Foundation of China (grant No.50171025) and by open project of foundation of National Key Laboratory of Metal Matrix Composite, Shanghai Jiao Tong University.
文摘Through the vacuum diffusion bonding for SiCp/ZLl01 aluminum matrix composite, the influence of bonding parameters on the joint properties was reported, with the aim to obtain optimal bonding parameters. The microstructureof joints was analyzed by means of optical microscope and scanning electron microscope in order to study the relationship between the macro-properties of joints and the microstructures. It was found that diffusion bonding couldbe used for bonding aluminum matrix composites successfully. Meanwhile, the properties of the matrix and the jointwere all affected by some defects such as the reinforcement aggregation in aluminum matrix composites made bystirring casting.
文摘TiC/ZA43 composites were fabricated by XD TM and stirring casting techniques. The tribology properties of the unreinforced ZA43 alloy and the composites were studied by using a block on ring apparatus. Experimental results show that the incorporation of TiC particles improves the microstructure of ZA43 matrix alloy. The coefficient of friction μ and the width of worn groove decrease with the increase of TiC volume fraction φ (TiC). The width of worn groove and μ of the composite during wear testing increase with increasing the applied load. Metallographic examinations reveal that unreinforced ZA43 alloy has deep ploughing grooves with obvious adhesion phenomenon, whereas TiC/ZA43 composites have smooth worn surface. Delamination formation is related to the fatigue cracks and the shear cracks on the surface. [
文摘SiCp/Gr/2024Al metal matrix composites were processed by squeeze casting technology. The microstructure of composites was observed by SEM and TEM, and the effects of graphite particulates and SiC particulates on the damping behaviors of composites were also investigated. The results show that the microstructure of composites was dense and homogeneous, without any interfacial reactivity among reinforcement/matrix interfaces. Compared with the damping capacity of 2024A1, the damping capacity of composites was enhanced significantly by addition of SiC or graphite particulates. The main damping mechanisms of SiCp/Al composites were ascribed to the dislocation damping, and those of SiCp/Gr/2024Al were attributed to the intrinsic damping and interface damping.
