Al-based composites reinforced with A1-Ti intermetallic compounds/Ti metal hierarchically spherical agents were successfully fabricated by powder metallurgy. This kind of structure produces strongly bonded interfaces ...Al-based composites reinforced with A1-Ti intermetallic compounds/Ti metal hierarchically spherical agents were successfully fabricated by powder metallurgy. This kind of structure produces strongly bonded interfaces as well as soft/hard/soft transition regions between the matrix and reinforced agents, which are beneficial to load transfer during deformation. As expected, the resultant composites exhibit promising mechanical properties at ambient temperature. The underlying mechanism was also discussed in this paper.展开更多
This study investigates the anisotropic thermal conductivity of aluminum matrix composites reinforced with graphene nano-plates(GNPs)and in situ ZrB_(2) nanoparticles,while simultaneously maintaining high strength and...This study investigates the anisotropic thermal conductivity of aluminum matrix composites reinforced with graphene nano-plates(GNPs)and in situ ZrB_(2) nanoparticles,while simultaneously maintaining high strength and toughness.A discontinuous layered GNPs-ZrB_(2)/AA6111 composite was prepared using in situ melt reactions and semi-solid stirring casting technology,combined with hot rolling deformation processing.Microstructural analysis revealed that the GNPs were aligned parallel to the rolling direction-transverse direction(RD-TD)plane,whereas the ZrB_(2) nanoparticles aggregated into cluster strips,collectively forming a discontinuous layered structure.This multilayer arrangement maximized the in-plane thermal conductivity of the GNPs.The tightly bonded GNP/Al interfaces with the locking of CuAl_(2) nanoparticles ensured that the GNPs fully exploited their high thermal conductivity.Therefore,the GNPs-ZrB_(2)/AA6111 composite achieved high in-plane thermal conductivity(230 W/(m·K)),which is higher than that of the matrix(206 W/(m·K)).The improved in-plane thermal conductivity is primarily attributed to the exceptionally high intrinsic in-plane thermal conductivity of the GNPs and their two-dimensional layered structure.However,the composite exhibited pronounced thermal conductivity anisotropy in the in-plane and through-plane directions.The reduced through-plane thermal conductivity is predominantly caused by the intrinsically low through-plane thermal conductivity of the GNPs and the increased interfacial thermal resistance from the additional grain boundaries.展开更多
Polymer matrix composites with high dielectric constants and low dielectric losses are in high demand for flexible electronics.However,simultaneously satisfying these requirements poses a significant scientific challe...Polymer matrix composites with high dielectric constants and low dielectric losses are in high demand for flexible electronics.However,simultaneously satisfying these requirements poses a significant scientific challenge owing to the intrinsic trade-off relationship.Herein,we utilized the in situ controllable reduction of graphene oxide(GO)within a poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene)(P(VDF-Tr FE-CFE))matrix to regulate the dielectric properties.The as-obtained composite exhibited a high relative dielectric constant of 1415coupled with a low loss tangent of 0.380 at 100 Hz.Experimental and theoretical studies indicate that the increased degree of electron conjugation and conductivity of the reduced GO(RGO)are responsible for the high-k.The constrained reduction degree of GO,combined with its homogeneous dispersion in the polymer matrix,effectively suppresses long-range charge carrier migration,thereby minimizing dielectric loss.This novel strategy could be successfully applied to both organic and aqueous systems.Furthermore,a high-performance flexible capacitive proximity sensor was exemplified by the optimization of both the dielectric layer and electrode pattern,exhibiting excellent sensitivity and stability.The fundamental mechanisms elucidated in this study provide crucial design principles for developing dielectric PMCs with tailored properties,thereby opening new avenues for advanced flexible electronic applications.展开更多
A new method for corrosion protection of Al-based metal matrix composites (MMC) was developed using two-step process, which involves anodizing in H2SO4 solution and sealing in rare earth solution. Corrosion resistance...A new method for corrosion protection of Al-based metal matrix composites (MMC) was developed using two-step process, which involves anodizing in H2SO4 solution and sealing in rare earth solution. Corrosion resistance of the treated surface was evaluated with polarization curves. The results showed that the effect of the protection using rare earth sealing is equivalent to that using chromate sealing for Al6061/SiCp. The rare earth metal salt can be an alternative to the toxic chromate for sealing anodized Al MMC.展开更多
Single-crystal(SC) structures have long been regarded as the optimal configuration for metal halide perovskite photodetectors(PDs);however, their applications in large-area imaging and wearable electronics face limita...Single-crystal(SC) structures have long been regarded as the optimal configuration for metal halide perovskite photodetectors(PDs);however, their applications in large-area imaging and wearable electronics face limitations due to size constraints and mechanical inflexibility. To address these challenges, this study develops a hybrid composite structure— polycrystalline powder(PCP) matrix(PCPM)—by strategically homogenizing 20 μm PCPs within a poly(methyl methacrylate) matrix. Such a configuration enables the formation of densely packed PCP microstructures while maintaining electric conductivity and mechanical flexibility. In the single-photon regime, responsivity(R) and external quantum efficiency(EQE) decline by 50%, with concurrent 3–4-fold enhancements in the On/Off ratio and 12–16-fold improvements in specific detectivity(D), compared with those of SC counterparts. Notably, in the two-photon regime, R and EQE exhibit a 2–3-fold increase, and the On/Off ratio and D exhibit 12–16-fold improvements. The PCPM configuration enables the high-repetitionrate wafer-scale fabrication of active layers for imaging PDs and provides exceptional mechanical flexibility and self-recovery. These findings establish PCPMs as a scalable platform for next-generation perovskite wearable electronics.展开更多
To exploit the combined strengthening effects of nanotwins and carbon nanotubes(CNTs)in Cu matrix composites,the nanotwins with a width ranging from 3 to 30 nm were incorporated into the CNTs-reinforced Cu matrix comp...To exploit the combined strengthening effects of nanotwins and carbon nanotubes(CNTs)in Cu matrix composites,the nanotwins with a width ranging from 3 to 30 nm were incorporated into the CNTs-reinforced Cu matrix composites using cryogenic rolling and optimizing the initial particle size of the raw Cu powders.The formation of nanotwins in the Cu matrix composite reinforced by only 0.2 wt.%CNTs is accompanied by the increased dislocation density and refined Cu grain size,resulting in much better strength−ductility synergy than the referenced composite without significant nanotwins formation.The analysis of strengthening and toughening mechanisms demonstrates that the strength increment mainly derives from grain refinement strengthening,dislocation strengthening,and nanotwin strengthening.The strength increment from the contribution of the nanotwins accounts for 19.9%of the overall strength increment for the composite.Meanwhile,the retention of good tensile ductility can be reasonably explained by the increased dislocation accommodation ability due to the formed nanotwins and the decreased induced dislocation proliferation.展开更多
Unmanned combat aerial vehicles require lightweight,stealth-capable exhaust systems.However,traditional metallic nozzles increase radar detectability and reduce range,while advanced composites offer high performance b...Unmanned combat aerial vehicles require lightweight,stealth-capable exhaust systems.However,traditional metallic nozzles increase radar detectability and reduce range,while advanced composites offer high performance but are expensive.Therefore,to improve the operational range and survivability of unmanned combat aerial vehicles,a lightweight,high-temperature-resistant,oxidation-resistant,and low-observable composite exhaust nozzle is developed to replace conventional metallic straight-type nozzles.The nozzle features a double serpentine shape to reduce radar and infrared signatures and is manufactured as a monolithic structure using the filament winding process,accommodating the complex geometry and large size(length:1.8 m,width:0.8 m).The exhaust nozzle consists of a ceramic matrix composite made of silicon carbide fibers and a silicon oxycarbide matrix,which absorbs and scatters radio frequency signals while withstanding prolonged exposure to high-temperature(700℃)oxidizing environments typical of engine exhaust gases.The polysiloxane resin used to produce the silicon oxycarbide matrix poses significant challenges owing to its low tackiness and high viscosity variations depending on the presence of nanoparticles,making filament winding difficult.These challenges are addressed by optimizing resin viscosity and winding pattern design.As a result,the tensile strength of the composite specimens fabricated with the optimized viscosity increases by 228.03% before pyrolysis and 97.68%after pyrolysis,compared with that of the non-optimized specimens.In addition,the density and tensile strength of the composite processed via three cycles of polymer infiltration and pyrolysis increased by 13.08% and 80.37%,respectively,compared to those of the non-densified composite.High-temperature oxidation and flame tests demonstrate exceptional thermal and oxidative stability.Furthermore,when compared with carbon fiber-reinforced ceramic matrix composites,the developed composite exhibits a permittivity at least two levels lower and a reflection loss below7 dB within the frequency range of 9.3-10.9 GHz,underscoring its superior electromagnetic stealth performance.展开更多
Graphene,as the reinforcing phase of magnesium matrix composites,can effectively improve the material strength,elastic modulus,and other properties.However,the random distribution of graphene in the matrix(i.e.,random...Graphene,as the reinforcing phase of magnesium matrix composites,can effectively improve the material strength,elastic modulus,and other properties.However,the random distribution of graphene in the matrix(i.e.,random orientation angle)leads to different reinforcement effects on the matrix.To gain a deeper understanding of the impact of monolayer graphene(1 LG)with varying orientation angles on the properties of Mg-9 Al-1 Zn(AZ91(wt.%))magnesium alloy,molecular dynamics(MD)simulations are employed to analyze the mechanical properties of AZ91/1 LG composites under uniaxial tension.The simulation results show that Young's modulus and tensile strength of AZ91/1 LG composites decrease gradually with the increase of the orientation angle of the 1 LG.The Young's modulus and tensile strength of AZ91/1 LG composites can be improved by the 1 LG orientation angle of 0°~10°,where the two are enhanced by 21.7%and 19.7%respectively,at an orientation angle of 0°.However,the Young's modulus and tensile strength of 1 LG are decreased for orientation angles of 20°~90°.Atomic structure evolution analysis revealed that the deformation mechanism of AZ91/1 LG nanocomposites mainly depended on the load transfer ability of 1 LG with different orientation angles,the bonding ability with AZ91 magnesium alloy matrix and the change of dislocation density.By fitting the formula to the tensile strength of AZ91/1 LG composites with different orientation angles of 1 LG,it is found that the simulated data of the AZ91/1 LG composites containing a 1 LG has a maximum relative error of about 10%concerning the fitted empirical formula to calculate the data.The maximum relative error for AZ91/1 LG composites containing multiplate 1 LG with different orientation angles is 7%.In addition,the interaction between graphene and dislocations in AZ91 magnesium matrix was further explained by transmission electron microscopy(TEM)and phase-field-crystal(PFC)simulation.It can provide some technical guidance for the experimental process design of AZ91/1 LG composites.展开更多
The in-situ Al-based composites with different SiO2/C/Al molar ratios were fabricated by reaction hot pressing. The dry sliding wear characteristics of the composites were investigated using a pin-on-disc wear tester....The in-situ Al-based composites with different SiO2/C/Al molar ratios were fabricated by reaction hot pressing. The dry sliding wear characteristics of the composites were investigated using a pin-on-disc wear tester. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to investigate the surface composition and its morphology. The results show that when the SiO2/C/Al molar ratio is 3:6:9, more in-situ synthesized Al2O3 and SiC along with Si particles are produced, and Al4C3 is prevented completely from the Al?SiO2?C system. Thereby, a significant improvement of wear resistance is obtained. When the sliding velocity increases from 0.4 to 1.6 m/s, the wear loss decreases gradually. With increasing the normal load, the wear loss increases as well. Ploughing, craters and micro-grooving are observed as dominant abrasive wear mechanisms. Whereas, when a high velocity is employed, only the oxidation mechanism controls the wear behavior of the composites.展开更多
The growing utilization of the ocean as a renewable energy source drives the need for reliable maritime infrastructure.One major challenge for these structures is withstanding impulsive loads from extreme ocean waves,...The growing utilization of the ocean as a renewable energy source drives the need for reliable maritime infrastructure.One major challenge for these structures is withstanding impulsive loads from extreme ocean waves,which requires materials with high strength and deformation resistance to maintain structural integrity.Metal Matrix Composite(MMC)is a promising material,yet studies on its behavior under impulsive loading remain limited.This study investigates the ultimate capacity of MMC sandwich structures using the Finite Element Method(FEM)through simulations with an Underwater Shock Loading Simulator(USLS).Validation against the results of He et al.confirms the accuracy of the simulation method.Results indicate that increasing flyer velocity from 135 to 195 m/s raises the maximum displacement from 5.83 mm to 10.7 mm.Increasing face sheet thickness from 0.4 to 1.8 mm reduces deformation from 4.95 to 3.09 mm,while increasing core thickness from 14 to 20 mm decreases deflection from 5.42 to 3.68 mm.Furthermore,the thickness ratio analysis indicates that the 1:10 configuration produces the smallest deformation(4.13 mm)and is more efficient because it provides higher stiffness with lower mass.These findings demonstrate that optimizing core and face sheet thickness significantly enhances structural resistance to deformation.The study concludes that a balanced thickness configuration is key to improving the structural performance of MMC sandwiches,supporting the design of stronger and more sustainable materials for maritime structures in extreme environments.展开更多
1.Introduction The strength-ductility trade-offdilemma has long been a per-sistent challenge in Al matrix composites(AMCs)[1,2].This is-sue primarily arises from the agglomeration of reinforcements at the grain bounda...1.Introduction The strength-ductility trade-offdilemma has long been a per-sistent challenge in Al matrix composites(AMCs)[1,2].This is-sue primarily arises from the agglomeration of reinforcements at the grain boundaries(GBs),which restricts local plastic flow dur-ing the plastic deformation and leads to stress concentration[3,4].Recently,the development of concepts aimed at achieving hetero-geneous grain has emerged as a promising approach for enhanc-ing comprehensive mechanical properties[5,6].展开更多
Graphene is considered promising reinforcement for improving the mechanical properties of the titanium alloys.However,overcoming the strength-ductility trade-off in graphene-reinforced titanium composites remains a ch...Graphene is considered promising reinforcement for improving the mechanical properties of the titanium alloys.However,overcoming the strength-ductility trade-off in graphene-reinforced titanium composites remains a challenge.In this study,the high-performance graphene nanoplatelets(GNPs)reinforced Ti-6Al-4V(TC4)matrix composites were successfully synthesized by combining the hot-pressing sintering and hot-rolling methods.Studies on the effect of GNPs on microstructures and properties of the as-sintered and as-rolled TC4 composites were systematically conducted.It indicates that the strength of the composites can be substantially enhanced by the addition of GNPs,primarily attributable to grain refinement and the pinning effect induced by in situ formed TiC particles.Moreover,the increase in the GNPs content results in a decrease in the plasticity of the as-sintered composites due to the aggregation of TiC.Additionally,hot rolling synchronously enhances the strength and plasticity of the composites by facilitating the homogeneous dispersion of TiC within the TC4 matrix.This work provided a potential strategy in designing the graphene-reinforced TC4 matrix composites with superior strength-ductility synergy.展开更多
Iron-based metal matrix composites(IMMCs)have attracted significant research attention due to their high specific stiffness and strength,making them potentially suitable for various engineering applications.Microstruc...Iron-based metal matrix composites(IMMCs)have attracted significant research attention due to their high specific stiffness and strength,making them potentially suitable for various engineering applications.Microstructural design,including the selection of reinforcement and matrix phases,the reinforcement volume fraction,and the interface issues are essential factors determining the engineering performance of IMMCs.A variety of fabrication methods have been developed to manufacture IMMCs in recent years.This paper reviews the recent advances and development of IMMCs with particular focus on microstructure design,fabrication methods,and their engineering performance.The microstructure design issues of IMMC are firstly discussed,including the reinforcement and matrix phase selection criteria,interface geometry and characteristics,and the bonding mechanism.The fabrication methods,including liquid state,solid state,and gas-mixing processing are comprehensively reviewed and compared.The engineering performance of IMMCs in terms of elastic modulus,hardness and wear resistance,tensile and fracture behavior is reviewed.Finally,the current challenges of the IMMCs are highlighted,followed by the discussion and outlook of the future research directions of IMMCs.展开更多
This work used 5CrMnMo steel and titanium carbide(TiC)powders to fabricate particulate metal matrix composites(PMMCS).The composites’microstructure,hardness,and impact toughness were compared with four different tita...This work used 5CrMnMo steel and titanium carbide(TiC)powders to fabricate particulate metal matrix composites(PMMCS).The composites’microstructure,hardness,and impact toughness were compared with four different titanium carbide ceramic particle sizes.The phase composition and microstructure of composites were studied.Vickers hardness and Charpy impact tests were employed to analyze composites’hardness and impact ductility,respectively.The results showed that the four groups of composites are mainly composed of martensite,trace residual austenite,and titanium carbide(undissolved TiC and primary TiC particles).With the growth of the ceramic particle dimension in the composite layer,the number of primary titanium carbide ceramics gradually decreased.When the initial ceramic particle size was small,it tended to generate dendritic primary TiC,and when the particle size was large,it tended to generate polygons and ellipsoids.Furthermore,with the growth of titanium carbide ceramic particle dimension in the composites,the hardness of the composites decreased but the impact toughness of the composites rose first and then descended.When the ceramic particle size was 50-75μm,the composite had the highest hardness,and the impact energy of the composites was the highest,which is 8 J.This was because there were more undissolved titanium carbide ceramics in the composite,and there was a thicker matrix metal between the ceramic particles.展开更多
To investigate the key factors that cause ZrB_(2)/AA6111 and(ZrB_(2)+Al_(3)Zr)/AA6111 aluminum matrix composites(AMCs)made via in situ reaction to behave differently in terms of friction and wear.Room-temperature dry ...To investigate the key factors that cause ZrB_(2)/AA6111 and(ZrB_(2)+Al_(3)Zr)/AA6111 aluminum matrix composites(AMCs)made via in situ reaction to behave differently in terms of friction and wear.Room-temperature dry sliding tribological behavior of AA6111 Al alloys,ZrB_(2)/AA6111,and(ZrB_(2)+Al_(3)Zr)/AA6111 AMCs against silicon nitride(Si_(3)N_(4))counterparts were investigated.The study showed that AA6111/Al alloy had the highest wear rate and the most unstable coefficient of friction(COF),indicating the worst abrasion resistance.(ZrB_(2)+Al_(3)Zr)/AA6111 AMCs exhibit a lower wear rate and higher COF than ZrB_(2)/AA6111 AMCs.The result proved that the Al_(3)Zr particles prepared by the in-situ reaction are strongly bonded(lattice misfitδ=2.7%)to the Al matrix and are not easily stripped from the substrate.ZrB_(2)/AA6111 AMCs exhibited a lower COF attributed to the tribochemical reaction inducing the formation of more boric acid(H_(3)BO_(3))films with a graphite-like structure having a lubricating effect.展开更多
Basalt fibers/7075 aluminum matrix composites were studied to meet the demand of aluminum alloy drill pipes for material wear resistance.The composites with different basalt fiber additions were prepared by hot presse...Basalt fibers/7075 aluminum matrix composites were studied to meet the demand of aluminum alloy drill pipes for material wear resistance.The composites with different basalt fiber additions were prepared by hot pressed sintering and hot extrusion.The mechanical properties as well as friction and wear properties of the composites were studied by microstructure analysis,tensile experiments,friction and wear experiments.The results showed that basalt fibers were oriented and uniformly distributed and led to local grain refinement in the alloy matrix.The hardness and elongation of the composites were improved.The friction coefficient of the composites increased and then decreased,and the maximum wear depth and wear amount decreased,then increased,then decreased again with the growth of basalt fiber addition.Meanwhile,the inclusion of basalt fibers mitigated the uneven wear of the extruded 7075 aluminum alloy.The value of wear depth difference of 7075-0.2BF was the smallest,and that of 7075-2.0BF was close to it.The maximum wear depth and wear volume the 7075-0.2BF and 7075-2.0BF were also the smallest.The inhibition of uneven wear by basalt fibers enhanced of wear resistance for 7075 aluminum alloy,which has reference significance for improving the performance of aluminum alloy drill pipes.展开更多
The effect of milling time on the microstructure and tribological properties of TiB_(2)−graphite hybrid reinforced Cu matrix composites was investigated.Hot-press sintering method was used to prepare the composites wi...The effect of milling time on the microstructure and tribological properties of TiB_(2)−graphite hybrid reinforced Cu matrix composites was investigated.Hot-press sintering method was used to prepare the composites with different milling time(4,6,8,10 and 12 h),and the tribological behaviors were studied.The results revealed that the relative density and electric conductivity of the composites initially increased and then decreased with an increase in milling time.The composites fabricated by milling for 6 h had the highest relative density and electric conductivity,which are 99.1%and 42.8%(IACS),respectively.The friction coefficient and wear rate of the composites initially decreased and then increased with an increase in milling time.The lowest friction coefficient and wear rate were measured to be 0.234 and 1.974×10^(−5)mm^(3)/(N·m),respectively,for the composites synthesized after 6 h of milling.The primary wear mechanism of the composites milled for 6 h was abrasive wear.展开更多
Hetero-deformation induced(HDI) strengthening generally yields a weak effect on the mechanical property improvement of particle-reinforced metal matrix composites(MMCs). In the present work, a novel strategy was repor...Hetero-deformation induced(HDI) strengthening generally yields a weak effect on the mechanical property improvement of particle-reinforced metal matrix composites(MMCs). In the present work, a novel strategy was reported to induce remarkable HDI strengthening in MMCs by selecting a reinforcing material with excellent geometrically necessary dislocation(GND) storage ability. The viability of the proposed strategy was tested on additively manufactured nickel matrix composites consisting of Inconel 625 alloy(IN625) as the matrix and high-entropy alloy VNbMoTa as the reinforcing material. It was found that the average grain size and dislocation density of the additively manufactured MMCs gradually decreased with the increase in the additional amount of VNbMoTa. All the samples possessed a similar two-layer VNbMoTa-matrix interface structure containing a high-entropy alloy layer and a Laves phase layer;however, the interface width varied. This two-layer interface could hold GND pile-ups without breaking to ensure a good load transfer effect, and ductile VNbMoTa particles demonstrated excellent GND storage capacity to induce significant HDI stress. The HDI stress for the IN625-(10 wt%)VNbMoTa sample was approximately 200 MPa higher than that for the pure IN625 alloy, resulting in an excellent strength-ductility synergy. The yield strength and elongation of the IN625-(10 wt%)VNbMoTa sample reached(1 032.5 ± 18.8)MPa and(11.8 ± 1.2)%, respectively. In addition, the IN625-(10 wt%)VNbMoTa composite also demonstrated superior mechanical properties at 650℃ that were comparable to those at room temperature, implying that VNbMoTa addition remarkably limited strength reduction caused by temperature. Deformable VNbMoTa particles effectively alleviated the stress concentration, delayed the crack initiation, generated more dislocations and pile-ups, and, in turn, improved the overall high-temperature strength of composites.展开更多
Magnesium matrix composites(MMCs)combine exceptional low density,high specific strength,and stiffness,positioning them as critical materials for aerospace,automotive,and electronics industries.This review highlights r...Magnesium matrix composites(MMCs)combine exceptional low density,high specific strength,and stiffness,positioning them as critical materials for aerospace,automotive,and electronics industries.This review highlights recent progress in the fabrication of Ti-Mg composites and analyzes the mechanisms behind their enhanced mechanical properties.A key focus is the interfacial deformation incompatibility between Ti and Mg phases,which generates strain gradients and promotes the accumulation of geometrically necessary dislocations(GNDs)at the interface.This process not only improves strain hardening and ductility but also reveals the need for advanced micromechanical models to capture the plastic behavior of both phases.The review critically examines the impact of different Mg matrix types(AZ,AM,VW series)and the role of interfacial product morphology and size on bonding and overall performance.Furthermore,Ti reinforcement endows the composites with superior wear resistance and thermal conductivity,indicating broad application potential.展开更多
The surface of MoSi2-SiB6/phenolic resin matrix composites was modified by mica,and the thermal oxidation behavior of the composites and the mechanical properties of the pyrolysis products were studied.The results sho...The surface of MoSi2-SiB6/phenolic resin matrix composites was modified by mica,and the thermal oxidation behavior of the composites and the mechanical properties of the pyrolysis products were studied.The results showed that the mica improved the thermal properties of the composites,the thermal expansion coefficient decreased,and the liquid phase formation caused the composites to shrink and increase the density.The flexural strength of mica surface modified composites not only increased to 78.64MPa after thermal treatment at 800-1200℃,but reached 83.02 MPa after high temperature treatment at1400℃.The improvement of the mechanical properties of the residual product benefits from the formation of high temperature ceramic phases such as Mo_(2)C and MoB,and the improvement of the shear strength of the composites by the mica.The shear strength of MBm5-2 at room temperature reached 33.08 MPa,indicating that the improvement of the interlayer properties of the composites further improved its mechanical properties.展开更多
文摘Al-based composites reinforced with A1-Ti intermetallic compounds/Ti metal hierarchically spherical agents were successfully fabricated by powder metallurgy. This kind of structure produces strongly bonded interfaces as well as soft/hard/soft transition regions between the matrix and reinforced agents, which are beneficial to load transfer during deformation. As expected, the resultant composites exhibit promising mechanical properties at ambient temperature. The underlying mechanism was also discussed in this paper.
基金supported by the National Natural Science Foundation of China(Nos.52471156,U20A20274,and 52071158)the China Postdoctoral Science Foundation(Nos.2024M751173 and 2024M752703)+1 种基金the Jiangsu Funding Program for Excellent Postdoctoral Talent,China(No.2024ZB229)the Natural Science Foundation of Jiangsu Higher Education Institutions,China(No.24KJB430012).
文摘This study investigates the anisotropic thermal conductivity of aluminum matrix composites reinforced with graphene nano-plates(GNPs)and in situ ZrB_(2) nanoparticles,while simultaneously maintaining high strength and toughness.A discontinuous layered GNPs-ZrB_(2)/AA6111 composite was prepared using in situ melt reactions and semi-solid stirring casting technology,combined with hot rolling deformation processing.Microstructural analysis revealed that the GNPs were aligned parallel to the rolling direction-transverse direction(RD-TD)plane,whereas the ZrB_(2) nanoparticles aggregated into cluster strips,collectively forming a discontinuous layered structure.This multilayer arrangement maximized the in-plane thermal conductivity of the GNPs.The tightly bonded GNP/Al interfaces with the locking of CuAl_(2) nanoparticles ensured that the GNPs fully exploited their high thermal conductivity.Therefore,the GNPs-ZrB_(2)/AA6111 composite achieved high in-plane thermal conductivity(230 W/(m·K)),which is higher than that of the matrix(206 W/(m·K)).The improved in-plane thermal conductivity is primarily attributed to the exceptionally high intrinsic in-plane thermal conductivity of the GNPs and their two-dimensional layered structure.However,the composite exhibited pronounced thermal conductivity anisotropy in the in-plane and through-plane directions.The reduced through-plane thermal conductivity is predominantly caused by the intrinsically low through-plane thermal conductivity of the GNPs and the increased interfacial thermal resistance from the additional grain boundaries.
基金financially supported by the Innovation and Technology Commission of the Hong Kong SAR Government(No.MRP/020/21)Hong Kong Polytechnic University(No.847A)+1 种基金RI-Wear Seed Fund of Poly U(1-CD8J)Start-up Fund of Poly U(1-BD49)。
文摘Polymer matrix composites with high dielectric constants and low dielectric losses are in high demand for flexible electronics.However,simultaneously satisfying these requirements poses a significant scientific challenge owing to the intrinsic trade-off relationship.Herein,we utilized the in situ controllable reduction of graphene oxide(GO)within a poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene)(P(VDF-Tr FE-CFE))matrix to regulate the dielectric properties.The as-obtained composite exhibited a high relative dielectric constant of 1415coupled with a low loss tangent of 0.380 at 100 Hz.Experimental and theoretical studies indicate that the increased degree of electron conjugation and conductivity of the reduced GO(RGO)are responsible for the high-k.The constrained reduction degree of GO,combined with its homogeneous dispersion in the polymer matrix,effectively suppresses long-range charge carrier migration,thereby minimizing dielectric loss.This novel strategy could be successfully applied to both organic and aqueous systems.Furthermore,a high-performance flexible capacitive proximity sensor was exemplified by the optimization of both the dielectric layer and electrode pattern,exhibiting excellent sensitivity and stability.The fundamental mechanisms elucidated in this study provide crucial design principles for developing dielectric PMCs with tailored properties,thereby opening new avenues for advanced flexible electronic applications.
文摘A new method for corrosion protection of Al-based metal matrix composites (MMC) was developed using two-step process, which involves anodizing in H2SO4 solution and sealing in rare earth solution. Corrosion resistance of the treated surface was evaluated with polarization curves. The results showed that the effect of the protection using rare earth sealing is equivalent to that using chromate sealing for Al6061/SiCp. The rare earth metal salt can be an alternative to the toxic chromate for sealing anodized Al MMC.
基金supported by the Key Project of the National Key R&D Program of China (Grant No.2022YFA1404500)the National Natural Science Foundation of China (Grant Nos.12434017,62005183)the Guangdong Basic and Applied Basic Research Foundation (Grant No.2025A1515010329)。
文摘Single-crystal(SC) structures have long been regarded as the optimal configuration for metal halide perovskite photodetectors(PDs);however, their applications in large-area imaging and wearable electronics face limitations due to size constraints and mechanical inflexibility. To address these challenges, this study develops a hybrid composite structure— polycrystalline powder(PCP) matrix(PCPM)—by strategically homogenizing 20 μm PCPs within a poly(methyl methacrylate) matrix. Such a configuration enables the formation of densely packed PCP microstructures while maintaining electric conductivity and mechanical flexibility. In the single-photon regime, responsivity(R) and external quantum efficiency(EQE) decline by 50%, with concurrent 3–4-fold enhancements in the On/Off ratio and 12–16-fold improvements in specific detectivity(D), compared with those of SC counterparts. Notably, in the two-photon regime, R and EQE exhibit a 2–3-fold increase, and the On/Off ratio and D exhibit 12–16-fold improvements. The PCPM configuration enables the high-repetitionrate wafer-scale fabrication of active layers for imaging PDs and provides exceptional mechanical flexibility and self-recovery. These findings establish PCPMs as a scalable platform for next-generation perovskite wearable electronics.
基金financially supported by the Fundamental Research Funds for the Central Universities,China(No.21624408)the Guangdong Basic and Applied Basic Research Foundation,China(Nos.2023A1515012850,2024A1515010416)+2 种基金Guangzhou Science and Technology Planning Project,China(No.2024A04J9966)the National Natural Science Foundation of China(Nos.52271132,52004101)the Key Laboratory of Advanced Materials of Yunnan Province,China(No.2024KF02)。
文摘To exploit the combined strengthening effects of nanotwins and carbon nanotubes(CNTs)in Cu matrix composites,the nanotwins with a width ranging from 3 to 30 nm were incorporated into the CNTs-reinforced Cu matrix composites using cryogenic rolling and optimizing the initial particle size of the raw Cu powders.The formation of nanotwins in the Cu matrix composite reinforced by only 0.2 wt.%CNTs is accompanied by the increased dislocation density and refined Cu grain size,resulting in much better strength−ductility synergy than the referenced composite without significant nanotwins formation.The analysis of strengthening and toughening mechanisms demonstrates that the strength increment mainly derives from grain refinement strengthening,dislocation strengthening,and nanotwin strengthening.The strength increment from the contribution of the nanotwins accounts for 19.9%of the overall strength increment for the composite.Meanwhile,the retention of good tensile ductility can be reasonably explained by the increased dislocation accommodation ability due to the formed nanotwins and the decreased induced dislocation proliferation.
基金supported by the Agency for Defense Development Grant Funded by the Korean Government(Grant No.912822501).
文摘Unmanned combat aerial vehicles require lightweight,stealth-capable exhaust systems.However,traditional metallic nozzles increase radar detectability and reduce range,while advanced composites offer high performance but are expensive.Therefore,to improve the operational range and survivability of unmanned combat aerial vehicles,a lightweight,high-temperature-resistant,oxidation-resistant,and low-observable composite exhaust nozzle is developed to replace conventional metallic straight-type nozzles.The nozzle features a double serpentine shape to reduce radar and infrared signatures and is manufactured as a monolithic structure using the filament winding process,accommodating the complex geometry and large size(length:1.8 m,width:0.8 m).The exhaust nozzle consists of a ceramic matrix composite made of silicon carbide fibers and a silicon oxycarbide matrix,which absorbs and scatters radio frequency signals while withstanding prolonged exposure to high-temperature(700℃)oxidizing environments typical of engine exhaust gases.The polysiloxane resin used to produce the silicon oxycarbide matrix poses significant challenges owing to its low tackiness and high viscosity variations depending on the presence of nanoparticles,making filament winding difficult.These challenges are addressed by optimizing resin viscosity and winding pattern design.As a result,the tensile strength of the composite specimens fabricated with the optimized viscosity increases by 228.03% before pyrolysis and 97.68%after pyrolysis,compared with that of the non-optimized specimens.In addition,the density and tensile strength of the composite processed via three cycles of polymer infiltration and pyrolysis increased by 13.08% and 80.37%,respectively,compared to those of the non-densified composite.High-temperature oxidation and flame tests demonstrate exceptional thermal and oxidative stability.Furthermore,when compared with carbon fiber-reinforced ceramic matrix composites,the developed composite exhibits a permittivity at least two levels lower and a reflection loss below7 dB within the frequency range of 9.3-10.9 GHz,underscoring its superior electromagnetic stealth performance.
基金supported by National Natural Science Foundation of China(Nos.52375394,52275390)Key Research and Development Program of Shanxi Province(Nos.202102050201011,2022ZDYF035)。
文摘Graphene,as the reinforcing phase of magnesium matrix composites,can effectively improve the material strength,elastic modulus,and other properties.However,the random distribution of graphene in the matrix(i.e.,random orientation angle)leads to different reinforcement effects on the matrix.To gain a deeper understanding of the impact of monolayer graphene(1 LG)with varying orientation angles on the properties of Mg-9 Al-1 Zn(AZ91(wt.%))magnesium alloy,molecular dynamics(MD)simulations are employed to analyze the mechanical properties of AZ91/1 LG composites under uniaxial tension.The simulation results show that Young's modulus and tensile strength of AZ91/1 LG composites decrease gradually with the increase of the orientation angle of the 1 LG.The Young's modulus and tensile strength of AZ91/1 LG composites can be improved by the 1 LG orientation angle of 0°~10°,where the two are enhanced by 21.7%and 19.7%respectively,at an orientation angle of 0°.However,the Young's modulus and tensile strength of 1 LG are decreased for orientation angles of 20°~90°.Atomic structure evolution analysis revealed that the deformation mechanism of AZ91/1 LG nanocomposites mainly depended on the load transfer ability of 1 LG with different orientation angles,the bonding ability with AZ91 magnesium alloy matrix and the change of dislocation density.By fitting the formula to the tensile strength of AZ91/1 LG composites with different orientation angles of 1 LG,it is found that the simulated data of the AZ91/1 LG composites containing a 1 LG has a maximum relative error of about 10%concerning the fitted empirical formula to calculate the data.The maximum relative error for AZ91/1 LG composites containing multiplate 1 LG with different orientation angles is 7%.In addition,the interaction between graphene and dislocations in AZ91 magnesium matrix was further explained by transmission electron microscopy(TEM)and phase-field-crystal(PFC)simulation.It can provide some technical guidance for the experimental process design of AZ91/1 LG composites.
基金Project (2012CB619600) supported by the Ministry of Science and Technology of ChinaProject (51201047) supported by the National Natural Science Foundation of China+1 种基金Project (HIT.NSRIF.2013001) supported by the Fundamental Research Funds for the Central Universities ChinaProject (20110491038) supported by the Postdoctoral Science Foundation of China
文摘The in-situ Al-based composites with different SiO2/C/Al molar ratios were fabricated by reaction hot pressing. The dry sliding wear characteristics of the composites were investigated using a pin-on-disc wear tester. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to investigate the surface composition and its morphology. The results show that when the SiO2/C/Al molar ratio is 3:6:9, more in-situ synthesized Al2O3 and SiC along with Si particles are produced, and Al4C3 is prevented completely from the Al?SiO2?C system. Thereby, a significant improvement of wear resistance is obtained. When the sliding velocity increases from 0.4 to 1.6 m/s, the wear loss decreases gradually. With increasing the normal load, the wear loss increases as well. Ploughing, craters and micro-grooving are observed as dominant abrasive wear mechanisms. Whereas, when a high velocity is employed, only the oxidation mechanism controls the wear behavior of the composites.
文摘The growing utilization of the ocean as a renewable energy source drives the need for reliable maritime infrastructure.One major challenge for these structures is withstanding impulsive loads from extreme ocean waves,which requires materials with high strength and deformation resistance to maintain structural integrity.Metal Matrix Composite(MMC)is a promising material,yet studies on its behavior under impulsive loading remain limited.This study investigates the ultimate capacity of MMC sandwich structures using the Finite Element Method(FEM)through simulations with an Underwater Shock Loading Simulator(USLS).Validation against the results of He et al.confirms the accuracy of the simulation method.Results indicate that increasing flyer velocity from 135 to 195 m/s raises the maximum displacement from 5.83 mm to 10.7 mm.Increasing face sheet thickness from 0.4 to 1.8 mm reduces deformation from 4.95 to 3.09 mm,while increasing core thickness from 14 to 20 mm decreases deflection from 5.42 to 3.68 mm.Furthermore,the thickness ratio analysis indicates that the 1:10 configuration produces the smallest deformation(4.13 mm)and is more efficient because it provides higher stiffness with lower mass.These findings demonstrate that optimizing core and face sheet thickness significantly enhances structural resistance to deformation.The study concludes that a balanced thickness configuration is key to improving the structural performance of MMC sandwiches,supporting the design of stronger and more sustainable materials for maritime structures in extreme environments.
基金support by the National Natural Science Foundation of China(Grant Nos.U23A20546 and 52271010)the Chinese National Natural Science Fund for Distinguished Young Scholars(Grant No.52025015)the Natural Science Foundation of Tianjin City(No.21JCZDJC00510).
文摘1.Introduction The strength-ductility trade-offdilemma has long been a per-sistent challenge in Al matrix composites(AMCs)[1,2].This is-sue primarily arises from the agglomeration of reinforcements at the grain boundaries(GBs),which restricts local plastic flow dur-ing the plastic deformation and leads to stress concentration[3,4].Recently,the development of concepts aimed at achieving hetero-geneous grain has emerged as a promising approach for enhanc-ing comprehensive mechanical properties[5,6].
基金supported by the National Key Research and Development Program of China(No.2023YFB3711000)the National Natural Science Foundation of China(Nos.52403364,52404369,W2411048 and 52171164)+3 种基金the Youth Innovation Promotion Association CAS(No.2021188)the Excellent Youth Fund of Liaoning Province(No.2024JH3/10200022)the China Postdoctoral Science Foundation(No.2024M753302)the IMR Innovation Fund(No.2024-PY18).
文摘Graphene is considered promising reinforcement for improving the mechanical properties of the titanium alloys.However,overcoming the strength-ductility trade-off in graphene-reinforced titanium composites remains a challenge.In this study,the high-performance graphene nanoplatelets(GNPs)reinforced Ti-6Al-4V(TC4)matrix composites were successfully synthesized by combining the hot-pressing sintering and hot-rolling methods.Studies on the effect of GNPs on microstructures and properties of the as-sintered and as-rolled TC4 composites were systematically conducted.It indicates that the strength of the composites can be substantially enhanced by the addition of GNPs,primarily attributable to grain refinement and the pinning effect induced by in situ formed TiC particles.Moreover,the increase in the GNPs content results in a decrease in the plasticity of the as-sintered composites due to the aggregation of TiC.Additionally,hot rolling synchronously enhances the strength and plasticity of the composites by facilitating the homogeneous dispersion of TiC within the TC4 matrix.This work provided a potential strategy in designing the graphene-reinforced TC4 matrix composites with superior strength-ductility synergy.
基金funding support from the National Natural Science Foundation of China(No.52101046)Shuangjie Chu appreciates the funding support from the National Key Research and Development Program of China(No.2022YFB3705600).
文摘Iron-based metal matrix composites(IMMCs)have attracted significant research attention due to their high specific stiffness and strength,making them potentially suitable for various engineering applications.Microstructural design,including the selection of reinforcement and matrix phases,the reinforcement volume fraction,and the interface issues are essential factors determining the engineering performance of IMMCs.A variety of fabrication methods have been developed to manufacture IMMCs in recent years.This paper reviews the recent advances and development of IMMCs with particular focus on microstructure design,fabrication methods,and their engineering performance.The microstructure design issues of IMMC are firstly discussed,including the reinforcement and matrix phase selection criteria,interface geometry and characteristics,and the bonding mechanism.The fabrication methods,including liquid state,solid state,and gas-mixing processing are comprehensively reviewed and compared.The engineering performance of IMMCs in terms of elastic modulus,hardness and wear resistance,tensile and fracture behavior is reviewed.Finally,the current challenges of the IMMCs are highlighted,followed by the discussion and outlook of the future research directions of IMMCs.
基金supported by the Equipment Pre-research and Sharing Technology(41423030503)provided funding for this workThe Equipment Pre-research and Sharing Technology(41423030503)funded this work.
文摘This work used 5CrMnMo steel and titanium carbide(TiC)powders to fabricate particulate metal matrix composites(PMMCS).The composites’microstructure,hardness,and impact toughness were compared with four different titanium carbide ceramic particle sizes.The phase composition and microstructure of composites were studied.Vickers hardness and Charpy impact tests were employed to analyze composites’hardness and impact ductility,respectively.The results showed that the four groups of composites are mainly composed of martensite,trace residual austenite,and titanium carbide(undissolved TiC and primary TiC particles).With the growth of the ceramic particle dimension in the composite layer,the number of primary titanium carbide ceramics gradually decreased.When the initial ceramic particle size was small,it tended to generate dendritic primary TiC,and when the particle size was large,it tended to generate polygons and ellipsoids.Furthermore,with the growth of titanium carbide ceramic particle dimension in the composites,the hardness of the composites decreased but the impact toughness of the composites rose first and then descended.When the ceramic particle size was 50-75μm,the composite had the highest hardness,and the impact energy of the composites was the highest,which is 8 J.This was because there were more undissolved titanium carbide ceramics in the composite,and there was a thicker matrix metal between the ceramic particles.
基金Supported by National Natural Science Foundation of China(Grant No.51605206)Postgraduate Research&Practice Innovation Program of Jiangsu Province of China(Grant Nos.SJCX21_1769,SJCX22_1941)Ministry of Science and Technology High-end Foreign Experts Introduction Program Project of China(Grant Nos.G2022014043,G2022014134L).
文摘To investigate the key factors that cause ZrB_(2)/AA6111 and(ZrB_(2)+Al_(3)Zr)/AA6111 aluminum matrix composites(AMCs)made via in situ reaction to behave differently in terms of friction and wear.Room-temperature dry sliding tribological behavior of AA6111 Al alloys,ZrB_(2)/AA6111,and(ZrB_(2)+Al_(3)Zr)/AA6111 AMCs against silicon nitride(Si_(3)N_(4))counterparts were investigated.The study showed that AA6111/Al alloy had the highest wear rate and the most unstable coefficient of friction(COF),indicating the worst abrasion resistance.(ZrB_(2)+Al_(3)Zr)/AA6111 AMCs exhibit a lower wear rate and higher COF than ZrB_(2)/AA6111 AMCs.The result proved that the Al_(3)Zr particles prepared by the in-situ reaction are strongly bonded(lattice misfitδ=2.7%)to the Al matrix and are not easily stripped from the substrate.ZrB_(2)/AA6111 AMCs exhibited a lower COF attributed to the tribochemical reaction inducing the formation of more boric acid(H_(3)BO_(3))films with a graphite-like structure having a lubricating effect.
基金Project(2021YFC2900200)supported by the National Key Research and Development Project of ChinaProject(20230203114SF)supported by the Key Research and Development Project of Jilin Province,China。
文摘Basalt fibers/7075 aluminum matrix composites were studied to meet the demand of aluminum alloy drill pipes for material wear resistance.The composites with different basalt fiber additions were prepared by hot pressed sintering and hot extrusion.The mechanical properties as well as friction and wear properties of the composites were studied by microstructure analysis,tensile experiments,friction and wear experiments.The results showed that basalt fibers were oriented and uniformly distributed and led to local grain refinement in the alloy matrix.The hardness and elongation of the composites were improved.The friction coefficient of the composites increased and then decreased,and the maximum wear depth and wear amount decreased,then increased,then decreased again with the growth of basalt fiber addition.Meanwhile,the inclusion of basalt fibers mitigated the uneven wear of the extruded 7075 aluminum alloy.The value of wear depth difference of 7075-0.2BF was the smallest,and that of 7075-2.0BF was close to it.The maximum wear depth and wear volume the 7075-0.2BF and 7075-2.0BF were also the smallest.The inhibition of uneven wear by basalt fibers enhanced of wear resistance for 7075 aluminum alloy,which has reference significance for improving the performance of aluminum alloy drill pipes.
基金the financial support from the Fundamental Research Funds for the Central Universities,China(Nos.21623416,21622110)the Science and Technology Research Program of Guangzhou,China(No.2024A04J3963)+2 种基金the National Natural Science Foundation of China(Nos.52271132,52373236,92166112)the Guangdong Basic and Applied Basic Research Foundation,China(Nos.2020A1515111067,2021A1515010890,2023A1515012850,2020B1515420004)the Open Fund of State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,China(No.20222410).
文摘The effect of milling time on the microstructure and tribological properties of TiB_(2)−graphite hybrid reinforced Cu matrix composites was investigated.Hot-press sintering method was used to prepare the composites with different milling time(4,6,8,10 and 12 h),and the tribological behaviors were studied.The results revealed that the relative density and electric conductivity of the composites initially increased and then decreased with an increase in milling time.The composites fabricated by milling for 6 h had the highest relative density and electric conductivity,which are 99.1%and 42.8%(IACS),respectively.The friction coefficient and wear rate of the composites initially decreased and then increased with an increase in milling time.The lowest friction coefficient and wear rate were measured to be 0.234 and 1.974×10^(−5)mm^(3)/(N·m),respectively,for the composites synthesized after 6 h of milling.The primary wear mechanism of the composites milled for 6 h was abrasive wear.
基金supported by National Natural Science Foundation of China(Grant No.52305419)Aeronautical Science Foundation Funded by Chinese Aeronautical Establishment(Grant No.2022Z0490T6001)+5 种基金Research Start-up Project of Xi’an University of Technology(Grant No.101-256082204)Technology Foundation for Selected Overseas Chinese Scholar(Grant No.2023-010)International Science and Technology Cooperation Program of Shaanxi Province(Grant No.2023-GHZD-50)Projects of Major Innovation Platforms for Scientific and Technological and Local Transformation of Scientific and Technological Achievements of Xi’an(Grant No.20GXSF0003)Higher Education Institution Discipline Innovation and Intelligence Base of Shaanxi Provincial(Grant No.S2021-ZCGXYZ-0011)Natural Science Basic Research Program of Shaanxi(Grant No.2023-JC-YB-412).
文摘Hetero-deformation induced(HDI) strengthening generally yields a weak effect on the mechanical property improvement of particle-reinforced metal matrix composites(MMCs). In the present work, a novel strategy was reported to induce remarkable HDI strengthening in MMCs by selecting a reinforcing material with excellent geometrically necessary dislocation(GND) storage ability. The viability of the proposed strategy was tested on additively manufactured nickel matrix composites consisting of Inconel 625 alloy(IN625) as the matrix and high-entropy alloy VNbMoTa as the reinforcing material. It was found that the average grain size and dislocation density of the additively manufactured MMCs gradually decreased with the increase in the additional amount of VNbMoTa. All the samples possessed a similar two-layer VNbMoTa-matrix interface structure containing a high-entropy alloy layer and a Laves phase layer;however, the interface width varied. This two-layer interface could hold GND pile-ups without breaking to ensure a good load transfer effect, and ductile VNbMoTa particles demonstrated excellent GND storage capacity to induce significant HDI stress. The HDI stress for the IN625-(10 wt%)VNbMoTa sample was approximately 200 MPa higher than that for the pure IN625 alloy, resulting in an excellent strength-ductility synergy. The yield strength and elongation of the IN625-(10 wt%)VNbMoTa sample reached(1 032.5 ± 18.8)MPa and(11.8 ± 1.2)%, respectively. In addition, the IN625-(10 wt%)VNbMoTa composite also demonstrated superior mechanical properties at 650℃ that were comparable to those at room temperature, implying that VNbMoTa addition remarkably limited strength reduction caused by temperature. Deformable VNbMoTa particles effectively alleviated the stress concentration, delayed the crack initiation, generated more dislocations and pile-ups, and, in turn, improved the overall high-temperature strength of composites.
基金the financial support from the National Key R&D Program of China(No.2022YFB3708400)National Natural Science Foundation of China(No.52171133,52225101)Basic and Applied Basic Research Foundation of Guangdong(No.2020B0301030006)。
文摘Magnesium matrix composites(MMCs)combine exceptional low density,high specific strength,and stiffness,positioning them as critical materials for aerospace,automotive,and electronics industries.This review highlights recent progress in the fabrication of Ti-Mg composites and analyzes the mechanisms behind their enhanced mechanical properties.A key focus is the interfacial deformation incompatibility between Ti and Mg phases,which generates strain gradients and promotes the accumulation of geometrically necessary dislocations(GNDs)at the interface.This process not only improves strain hardening and ductility but also reveals the need for advanced micromechanical models to capture the plastic behavior of both phases.The review critically examines the impact of different Mg matrix types(AZ,AM,VW series)and the role of interfacial product morphology and size on bonding and overall performance.Furthermore,Ti reinforcement endows the composites with superior wear resistance and thermal conductivity,indicating broad application potential.
基金Funded by the National Natural Science Foundation of China(Nos.52171045,52162013,and 51932006)。
文摘The surface of MoSi2-SiB6/phenolic resin matrix composites was modified by mica,and the thermal oxidation behavior of the composites and the mechanical properties of the pyrolysis products were studied.The results showed that the mica improved the thermal properties of the composites,the thermal expansion coefficient decreased,and the liquid phase formation caused the composites to shrink and increase the density.The flexural strength of mica surface modified composites not only increased to 78.64MPa after thermal treatment at 800-1200℃,but reached 83.02 MPa after high temperature treatment at1400℃.The improvement of the mechanical properties of the residual product benefits from the formation of high temperature ceramic phases such as Mo_(2)C and MoB,and the improvement of the shear strength of the composites by the mica.The shear strength of MBm5-2 at room temperature reached 33.08 MPa,indicating that the improvement of the interlayer properties of the composites further improved its mechanical properties.
