Combining high conductivity,hydrophilicity and excellent electrochemical perfo rmance in one,MXe nes have attracted increasing attention since their inception.However,easy to stack caused by the van der Waals’force b...Combining high conductivity,hydrophilicity and excellent electrochemical perfo rmance in one,MXe nes have attracted increasing attention since their inception.However,easy to stack caused by the van der Waals’force between the layers limits their practical application.Fortunately,intercalating other substances between layers of MXe nes and getting intercalated MXene-based layered composites(IMLCs)with open structure can improve their physical and chemical properties effectively.Larger available surface helps expose more active sites and enlarged layer spacing facilitates ion transport.In addition,other substances fixed in the interlayers by MXenes’two-dimensional confinement effect can produce synergistic effect and expand their applicable range greatly.This review is dedicated to summarizing the preparation methods and applications of IMLCs,emphasizing the advantages of them in the fields of energy storage,catalysis,sensors,electromagnetic interference(EMI)shielding and biomedicine.Furthermore,prospects and further developments in these gratifying fields are also commented.展开更多
The interaction of anti-plane elastic SH waves with a periodic array of interface cracks in a multi-layered periodic medium is analyzed in this paper. A perfect periodic structure without interface cracks is first stu...The interaction of anti-plane elastic SH waves with a periodic array of interface cracks in a multi-layered periodic medium is analyzed in this paper. A perfect periodic structure without interface cracks is first studied and the transmission displacement coefficient is obtained based on the transfer matrix method in conjunction with the Bloch-Floquet theorem. This is then generalized to a single and periodic distribution of cracks at the center interface and the result is compared with that of perfect periodic cases without interface cracks. The dependence of the transmission displacement coefficient on the frequency of the incident wave, the influences of material combination, crack configuration and incident angle are discussed in detail. Compared with the corresponding perfect periodic structure without interface cracks, a new phenomenon is found in the periodic layered system with a single and periodic array of interface cracks.展开更多
A357-SiCp/A357 layered composites were prepared using a semi-solid vacuum stirring suction casting method.The microstructures,mechanical properties,and thermal conductivities of the composites fabricated under differe...A357-SiCp/A357 layered composites were prepared using a semi-solid vacuum stirring suction casting method.The microstructures,mechanical properties,and thermal conductivities of the composites fabricated under different suction casting processes were compared.Additionally,the microstructural evolution characteristics and performance enhancement mechanism of the A357-SiCp/A357 layered composites were discussed.The results demonstrate that suction casting at 610°C with a low solid phase ratio can significantly enhance the material density and reduce the agglomeration of SiCp.The A357-SiC_(p)/A357 interface is clear and straight with good bonding.With an increase in the suction casting temperature,the bending resistance and thermal conductivity of the A357-SiC_(p)/A357 layered composites exhibit a trend of significantly increase at first and then slowly decrease owing to casting defects,interface bonding,and SiCp distribution.Compared with SiCp/A357 composites,the bending strength,deflection,and thermal conductivity of the A357-SiCp/A357 layered composites increase from 257 MPa,1.07 mm,and 155.72 W·(m·K)^(-1) to 298 MPa,2.1 mm,and 169.86 W·(m·K)^(-1),respectively.This study provides a reference for improving the rheological casting of aluminum matrix layered composites.展开更多
The effect of height on performance of the PZT/Ni cylindrical bilayered magnetoelectric （ME） com- posites was studied in situ in this paper. Multiple resonant peaks appear between 1 and 300 kHz frequency for cyl- in...The effect of height on performance of the PZT/Ni cylindrical bilayered magnetoelectric （ME） com- posites was studied in situ in this paper. Multiple resonant peaks appear between 1 and 300 kHz frequency for cyl- inders of different heights. The first resonance frequency does not change with the cylinder height decreasing, but the second and the third resonant frequencies increase. The first three resonant modes radial, first-order height are attributed to the cylinder resonance, and second-order height resonance, respectively. The appropriate size and resonance frequency were chosen to obtain the highest ME voltage coefficient when designing cylindrical bilayered magnetoelectric devices. This article provides reference to design cylindrical magnetoelectric devices.展开更多
Total resection of glioblastoma(GB)tumors is nearly impossible,and systemic administration of temozolomide(TMZ)is often inadequate.This study presents a hybrid layered composite nanofiber network(LHN)designed for loca...Total resection of glioblastoma(GB)tumors is nearly impossible,and systemic administration of temozolomide(TMZ)is often inadequate.This study presents a hybrid layered composite nanofiber network(LHN)designed for localized treatment in GB tumor bed.The LHN,consisting of polyvinyl alcohol and core-shell polylactic acid layers,was loaded with TMZ and rutin.In vitro analysis revealed that LHN^(TMZ) and LHNrutin decelerated epithelial-mesenchymal transition and growth of stem-like cells,while the combination,LHN^(TMZ)+rutin,significantly reduced sphere size compared to untreated and LHNTMZ-treated cells(P<0.0001).In an orthotopic C6-induced GB rat model,LHNTMZ+rutin therapy demonstrated a more pronounced tumor-reducing effect than LHNTMZ alone.Tumor volume,assessed by magnetic resonance imaging,was significantly reduced in LHN^(TMZ)+rutin-treated rats compared to untreated controls.Structural changes in tumor mitochondria,reduced membrane potential,and decreased PARP expression indicated the activation of apoptotic pathways in tumor cells,which was further confirmed by a reduction in PHH3,indicating decreased mitotic activity of tumor cells.Additionally,the local application of LHNs in the GB model mitigated aggressive tumor features without causing local tissue inflammation or adverse systemic effects.This was evidenced by a decrease in the angiogenesismarker CD31,the absence of inflammation or necrosis in H&E staining of the cerebellum,increased production of IFN-γ,decreased levels of interleukin-4 in splenic T cells,and lower serum AST levels.Our findings collectively indicate that LHN^(TMZ)+rutin is a promising biocompatible model for the local treatment of GB.展开更多
The effects of a magnesium-based layered composite on the flammability of a phenolic epoxy resin(EP)are studied.In order to produce the required composite material,first,magnesium hydroxide,aluminum salt and deionized...The effects of a magnesium-based layered composite on the flammability of a phenolic epoxy resin(EP)are studied.In order to produce the required composite material,first,magnesium hydroxide,aluminum salt and deionized water are mixed into a reactor according to a certain proportion to induce a hydrothermal reaction;then,the feed liquid is filtered out using a solid-liquid separation procedure;finally,the material is dried and crushed.In order to evaluate its effects on the flammability of the EP,first,m-phenylenediamine is added to EP and vacuum defoamation is performed;then,EP is poured into a polytetrafluoroethylene mold,cooled to room temperature and demoulded;finally,the magnesium-based layered composite is added to EP,and its flame retardance is characterized by thermogravimetric analysis,limiting oxygen index and cone calorimetry.The X-ray diffraction patterns show that the baseline of magnesium-based layered composite is stable and the front shape is sharp and symmetrical when the molar ratio of magnesium to aluminium is 3.2:1;with the addition of magnesium-based layered composite,the initial pyrolysis temperature of EP of 10%,15%and 30%magnesium-based layered composite decreases to 318.2°C,317.9°C and 357.1°C,respectively.After the reaction,the amount of residual carbon increases to 0.1%,3.45%and 8.3%,and the limiting oxygen index increases by 28.3%,29.1%and 29.6%,respectively.The maximum heat release rate of cone calorimeter decreases gradually.The optimum molar ratio of Mg:Al for green synthesis is 3.2:1,and the NO_(3)-intercalated magnesium-based layered composite has the best flame retardance properties.展开更多
Ag-based braze alloy has emerged as a promising filler for the fabrication of key components through joining between dissimilar materials,including but not limited to metals,ceramic,glass,graphite,diamond and C/C comp...Ag-based braze alloy has emerged as a promising filler for the fabrication of key components through joining between dissimilar materials,including but not limited to metals,ceramic,glass,graphite,diamond and C/C composite.A tremendous effort has been employed to develop new types of Ag-based braze alloy and composite braze alloy with desirable properties.However,the continuous emergence of new materials,extreme complexity of brazing structure and extreme severity of service environment continuously addresses new challenges for the new materials under extreme conditions,including the poor wettability,excessive brittle phase,high residual stress and deteriorated property of brazed joints,hindering the development of key components.This review is anticipated to deliver new guidelines for the design and utilization of Ag-based braze alloy and composite braze alloy toward the practical application in brazing with a desirable performance.Additionally,perspectives on future Ag-based braze alloy development are discussed.展开更多
It has always been challenging work to reconcile the contradiction between the strength and plasticity of titanium materials.Laser powder bed fusion(LPBF) is a convenient method to fabricate innovative composites incl...It has always been challenging work to reconcile the contradiction between the strength and plasticity of titanium materials.Laser powder bed fusion(LPBF) is a convenient method to fabricate innovative composites including those inspired by gradient layered materials.In this work,we used LPBF to selectively prepare Ti N/Ti gradient layered structure(GLSTi)composites by using different N_(2)–Ar ratios during the LPBF process.We systematically investigated the mechanisms of in-situ synthesis Ti N,high strength and ductility of GLSTi composites using microscopic analysis,TEM characterization,and tensile testing with digital image correlation.Besides,a digital correspondence was established between the N_(2) concentration and the volume fraction of LPBF in-situ synthesized Ti N.Our results show that the GLSTi composites exhibit superior mechanical properties compared to pure titanium fabricated by LPBF under pure Ar.Specifically,the tensile strength of GLSTi was more than 1.5times higher than that of LPBF-formed pure titanium,reaching up to 1100 MPa,while maintaining a high elongation at fracture of 17%.GLSTi breaks the bottleneck of high strength but low ductility exhibited by conventional nanoceramic particle-strengthened titanium matrix composites,and the hetero-deformation induced strengthening effect formed by the Ti N/Ti layered structure explained its strength-plasticity balanced principle.The microhardness exhibits a jagged variation of the relatively low hardness of 245 HV0.2 for the pure titanium layer and a high hardness of 408 HV0.2 for the N_(2) in-situ synthesis layer.Our study provides a new concept for the structure-performance digital customization of 3D-printed Ti-based composites.展开更多
Theoretical analysis and numerical calculations of Love wave propagation in layered graded composites with imperfectly bonded interface are described in this paper. On the basis of WKB method, the approximate analytic...Theoretical analysis and numerical calculations of Love wave propagation in layered graded composites with imperfectly bonded interface are described in this paper. On the basis of WKB method, the approximate analytic solutions for Love waves are obtained. By the interface shear spring model, the dispersion relations for Love waves in layered graded composite structures with rigid, slip, and imperfectly bonded interfaces are given, and the effects of the interface conditions on the phase velocities of Love waves in SiC/Al layered graded composites are discussed. Numerical analysis shows that the phase velocity decreases when the defined flexibility parameter is greater. For the general imperfectly bonded interface, the phase velocity changes in the range of the velocities for the rigid and slip interface conditions.展开更多
Relatively well crystallized and high aspect ratio Mg-Al layered double hydroxides（LDHs） were prepared by coprecipitation process in aqueous solution and further rehydrated to an organic modified LDH（OLDH） in the ...Relatively well crystallized and high aspect ratio Mg-Al layered double hydroxides（LDHs） were prepared by coprecipitation process in aqueous solution and further rehydrated to an organic modified LDH（OLDH） in the presence of surfactant. The intercalated structure and high aspect ratio of OLDH were verified by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. A series of poly（propylene carbonate）（PPC）/OLDH composite films with different contents of OLDH were prepared via a melt-blending method. Their cross section morphologies, gas barrier properties and tensile strength were investigated as a function of OLDH contents. SEM results show that OLDH platelets are well dispersed within the composites and oriented parallel to the composite sheet plane. The gas barrier properties and tensile strength are obviously enhanced upon the incorporation of OLDH. Particularly, PPC/2%OLDH film exhibits the best barrier properties among all the composite films. Compared with pure PPC, the oxygen permeability coefficient（OP） and water vapor permeability coefficient（WVP） is reduced by 54% and 17% respectively with 2% OLDH addition. Furthermore, the tensile strength of PPC/2%OLDH is 83% higher than that of pure PPC with only small lose of elongation at break. Therefore, PPC/OLDH composite films show great potential application in packaging materials due to its biodegradable properties, superior oxygen and moisture barrier characteristics.展开更多
Methods: 80 patients with anterior teeth defect (80 teeth) were selected from June 2018 to June 2020. The patients were randomly divided into two groups, 40 patients in each group (40 teeth). The control group was tre...Methods: 80 patients with anterior teeth defect (80 teeth) were selected from June 2018 to June 2020. The patients were randomly divided into two groups, 40 patients in each group (40 teeth). The control group was treated with conventional composite resin, while the observation group was treated with aesthetic composite resin layered plasticization. The success rate, satisfaction score, periodontal health status, pink aesthetic index (PES) score and complications occurred. Results: the success rate of repair in the observation group was higher than that in the control group (95%vs75%) (χ26.275, P 0.012 < 0.05). the satisfaction scores at the completion of repair and 3 months after repair were higher than those in the control group (P < 0.05). Three months after restoration, the number of periodontal health related indicators in the observation group was lower than that in the control group (P < 0.05). There was no significant difference in PES scores between the two groups before treatment (P > 0.05). The PES scores of the two groups were significantly higher at 12 and 24 months after treatment than before treatment (P < 0.05). The PES scores of the observation group were higher than those of the control group at 12 and 24 months after treatment (P < 0.05). After 2 years of follow-up, the observation group had complications such as prosthesis cutting, prosthesis discoloration, exogenous coloring, tooth sensitivity, while the control group had complications such as filling loss, pulpitis, dental caries, prosthesis discoloration, exogenous coloring, etc. The incidence of complications in the observation group (20%vs25%) was lower than that in the control group, but the difference was not statistically significant (P > 0.05). Conclusion: the aesthetic composite resin layered plasticizing technique has the advantages of high success rate, high satisfaction and good periodontal health. It is superior to the conventional composite resin restoration technique and is worthy of clinical promotion.展开更多
Aseries of [(Fe_(0.6)Co_(0.2)Ni_(0.2))_(0.75-0.03x)B_(0.2)Si_(0.05+0.03x)]_(96)Nb_(4) amorphous alloy composite coatings were prepared by adjusting the silicon content(x=0,1,2,3,4,5,and 6)and their microstructures and...Aseries of [(Fe_(0.6)Co_(0.2)Ni_(0.2))_(0.75-0.03x)B_(0.2)Si_(0.05+0.03x)]_(96)Nb_(4) amorphous alloy composite coatings were prepared by adjusting the silicon content(x=0,1,2,3,4,5,and 6)and their microstructures and tribological properties were investigated by laser cladding technique.Additionally,the effect of Si on the glass forming ability(GFA)of the layers was understood.Results show that an appropriate Si content can refine the microstructure of the FeCoNiBSiNb laser cladding layers and improve the mechanical and tribological properties.The hardness of the coating layer increases monotonically with the Si content.At the Si content of 4.8at%(x=0),the coating layer exhibits a relatively low hardness(734.2HV 0.1).Conversely,at the silicon content of 13.44at%(x=3),the coating layer exhibits the highest hardness(1106HV 0.1).The non-crystalline content and tensile strength exhibit an initial increase,followed by a subsequent decrease.At x=2,the coating exhibits its maximum fracture strength(2880 MPa).However,when x>2,the fracture strength of the coating decreases with an increase in x.Conversely,with an increase in Si content,the wear volume loss initially decreases and then increases.At a Si content of 10.56at%(x=2),the coating exhibits the highest non-crystalline content(42%),the highest tensile strength(2880 MPa),and the most favorable dry friction performance.展开更多
Because of an unfortunate mistake during the production of this article,the Acknowledgements have been omitted.The Acknowledgements are added as follows:Sasan YAZDANI would like to thank the Scientific and Technologic...Because of an unfortunate mistake during the production of this article,the Acknowledgements have been omitted.The Acknowledgements are added as follows:Sasan YAZDANI would like to thank the Scientific and Technological Research Council of Turkey(TÜB˙ITAK)for receiving financial support for this work through the 2221 Fellowship Program for Visiting Scientists and Scientists on Sabbatical Leave(Grant ID:E 21514107-115.02-228864).Sasan YAZDANI also expresses his gratitude to Sahand University of Technology for granting him sabbatical leave to facilitate the completion of this research.展开更多
In order to enhance the wear resistance of 45 steel,a WC/Stellite 6 composite layer with 30%WC which with different morphologies(spherical and irregular)was prepared on the surface of 45 steel by laser cladding techno...In order to enhance the wear resistance of 45 steel,a WC/Stellite 6 composite layer with 30%WC which with different morphologies(spherical and irregular)was prepared on the surface of 45 steel by laser cladding technology.The effects of WC morphology on the phase composition,microstructure,microhardness,and wear resistance of the cladding layer were compared and analyzed.The res-ults show that the surface of the cladding layer was well formed.M_(23)C_(6),M_(7)C_(3),WC,and W_(2)C exist in both cladding layers.With the ad-dition of spherical WC,the diffraction peaks of γ-Co appear on the left side of the main peak of Co6W6C.The area of intergranular carbides accounts for a large proportion in the surface layer which with the fine grains.During the process of laser cladding the spherical WC particles with loose structure are prone to melting,including their interior.However,the melting amount of irregular WC particles is finite,which only occurs on the periphery of the particles,and the particle interior is relatively intact.The microhard-ness of two cladding layers gradient increases from the substrate to the surface layer.The surface layer added spherical WC has high-er microhardness,which reaches 790.6 HV1.Nevertheless,the wear resistance of the cladding layer added irregular WC is better than that of the cladding layer added spherical WC.The reason is because that the incompletely melted irregular WC particles are uni-formly distributed in the cladding layer which provided the support points for the cladding layer matrix during the wear process,the wear of the cladding layer by the grinding pair is reduced consequently.展开更多
This study introduces an innovative composite cathode catalyst layer(CCL)design for proton exchange membrane fuel cells(PEMFCs),combining Pt-supported by Vulcan carbon(Pt/V)and Ketjenblack carbon(Pt/KB)to overcome mas...This study introduces an innovative composite cathode catalyst layer(CCL)design for proton exchange membrane fuel cells(PEMFCs),combining Pt-supported by Vulcan carbon(Pt/V)and Ketjenblack carbon(Pt/KB)to overcome mass transport limitations and ionomer-induced catalyst poisoning.The composite architecture strategically positions Pt/V layer with lower ionomer-to-carbon ratio(I/C=0.6)near the proton exchange membrane to maximize surface Pt accessibility and oxygen transport efficiency,whereas Pt/KB layer(I/C=0.9)adjacent to the gas diffusion layer leverages its porous structure to shield Pt from sulfonate group poisoning and enhance proton conduction under low-humidity conditions.This synergistic carbon support engineering achieves a balance between reactant accessibility and catalyst utilization,as demonstrated by improved power density,reduced transport resistance,and higher Pt utilization under dry conditions.These findings establish a new paradigm for low-Pt CCL design through rational carbon support hybridization and ionomer gradient engineering,offering a scalable solution for high-performance PEMFCs in energy-critical applications.展开更多
Large area diamond films were fabricated on copper substrates by a multi-step process comprised of electroplating Cu-diamond composite layer on Cu substrate, plating a Cu layer to fix the protruding diamond particles,...Large area diamond films were fabricated on copper substrates by a multi-step process comprised of electroplating Cu-diamond composite layer on Cu substrate, plating a Cu layer to fix the protruding diamond particles, and depositing continuous diamond film on composite interlayer by hot-filament chemical vapor deposition （HFCVD）. The interface characteristics, internal stress and adhesion strength were investigated by scanning electron microscopy, Raman analysis and indentation test. The results show that the continuous film without cracks is successfully obtained. The microstructure of the film is a mixture of large cubo-octahedron grains grown from homo-epitaxial growth and small grains with （111） apparent facets grown from lateral second nuclei. The improved adhesion between diamond film and substrate results from the deep anchoring of the diamond particles in the Cu matrix and the low residual stress in the film.展开更多
A three-dimensional plasticity model was developed and applied to metal-intermetallic laminate composites containingphases of the L12 structure. A multi-scale approach that combined the methods of continuum mechanics ...A three-dimensional plasticity model was developed and applied to metal-intermetallic laminate composites containingphases of the L12 structure. A multi-scale approach that combined the methods of continuum mechanics and dislocationkinetics was used. This model takes account of the different mechanisms of self-locking superdislocations, the dislocationsand the dislocation walls＇ density storage for each type of layer at the micro-scale. At the meso-scale, the solutions to thedislocation kinetics equations, in the form of stress-strain curves, were used to create the properties of a three-dimensionalrepresentative element. The numerical simulation study of the macroscopic deformation was carried out with the finiteelement method using the dynamic model of continuum mechanics, which included the classical conservation laws,constitutive equations and the equation of state. It was shown that the simulation results generated using this model were ingood agreement with the mechanical tests conducted on the single crystals of the L12 structure. The model provides anexcellent description of the high-temperature plastic strain superlocalization effect of single crystal intermetallics of theLI2 structure. This paper describes the numerical results of the study of the tension and compression tests of metal-intermetallic laminate composites containing phases of the L12 structure. The model allows the description of the dis-tribution of the accumulated plastic strain inhomogeneities and is capable of predicting the strengthening properties andplastic behaviour of the metal-intermetallic laminate composites containing phases of the L12 structure.展开更多
A concave die with an equal-strain contour line was used in the hydrostatic extrusion process to deform the two-layer Cu/A1 composite. The extruding process was simulated using the fi- nite element method （FEM）. The...A concave die with an equal-strain contour line was used in the hydrostatic extrusion process to deform the two-layer Cu/A1 composite. The extruding process was simulated using the fi- nite element method （FEM）. The effect of the friction coefficients on the relative slippage of the contact surfaces between the internal and external metals was investigated, and the stress distribu- tion in the extruded specimen was studied. The simulation results reveal that the relative slippage de- creases with increasing friction coefficient at the contact surface of the two metals. However, the relative slippage increases rapidly with increasing friction coefficient at the contact surface between the specimen and die. No axial tensile stress appears in the plastic deformation zone near the axis, indicating that the inner fracture will not occur in internal metal in the hydrostatic extrusion process as the concave die with equal-strain contour lines is used. The experimental test reveals that the met- allurgical bond is formed between Cu and A1 when the friction coefficient at the surface between the two metals is 0. 3 and the extrusion ratio is 12.展开更多
A low carbon steel （LCS）/high chromium white cast iron （HCCI） bimetal wear plate about 20 mm in thickness was prepared by liquid-liquid bimetal composite casting technology to substitute for the welding wear plate...A low carbon steel （LCS）/high chromium white cast iron （HCCI） bimetal wear plate about 20 mm in thickness was prepared by liquid-liquid bimetal composite casting technology to substitute for the welding wear plate. A clear and distinguishable composite layer between the LCS and the HCCI was detected with SEM, and the composition and phase were analyzed through EDS and XRD. The composite layer was composed of three sublayers from the LCS to the HCCI： pearlite transition layer, composite layer, and HCCI transition layer. The Vickers hardness from the pearlite transition layer to the HCCl transition layer was 360 HV to 855 HV. The austenite grows as dendrites between the composite layer and the HCCI transition layer under constitutional undercooling. A large amount of C and Cr, and a small amount of Si and Mn dissolve in the matrix. Granular Cr7C3 is uniformly distributed. Due to the solute redistribution at the solid-liquid interface, the primary austenite grows from planar to cellular and finally to the distinct dendrite crystals. The dendrite crystals have an obvious growth direction perpendicular to the composite layer.展开更多
The surface infiltrated composite （Ni/WC） layers on gray iron substrate were fabricated through a vacuum infiltration casting technique （VICT） using Ni-based composite powder with different WC particles content as...The surface infiltrated composite （Ni/WC） layers on gray iron substrate were fabricated through a vacuum infiltration casting technique （VICT） using Ni-based composite powder with different WC particles content as raw materials.The microstructures of surface infiltrated composite layer,the interface structures between surface composite layer and the substrate,the changes of macro-hardness with the increasing of WC content and the micro-hardness distribution are investigated.The infiltrated composite layer includes a surface composite layer and a transition layer,and the thickness of the transition layer decreases with the increasing content of WC.The thickness of transition layer with 20%WC content in the surface infiltrated composite layer was 170 μm which was the thickest for all transition layers with different WC content.The surface composite layer was mainly composed of WC,W2C,FeB and NiB,along with Ni-Cr-Fe,Ni （Cr） solid solution,Ni （Si） solid solution and Ni （Fe） solid solution.The transition layer was composed of Ni （Cr） solid solution,Ni （Fe） solid solution,Ni （Si） solid solution,Fe （Ni） solid solution and eutectic.The surface macro-hardness and micro-hardness of the infiltrated layer had been evaluated.The macro-hardness of the surface composite layer decreases with the WC content increasing,and the average macro-hardness is HRC60.The distribution of micro-hardness presents gradient change.The average micro-hardness of the infiltrated layer is about HV1000.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21776061,21978069,21707081 and 41807128)the program for Science&Technology Innovation Team in Universities of Henan Province(No.19IRTSTHN029)。
文摘Combining high conductivity,hydrophilicity and excellent electrochemical perfo rmance in one,MXe nes have attracted increasing attention since their inception.However,easy to stack caused by the van der Waals’force between the layers limits their practical application.Fortunately,intercalating other substances between layers of MXe nes and getting intercalated MXene-based layered composites(IMLCs)with open structure can improve their physical and chemical properties effectively.Larger available surface helps expose more active sites and enlarged layer spacing facilitates ion transport.In addition,other substances fixed in the interlayers by MXenes’two-dimensional confinement effect can produce synergistic effect and expand their applicable range greatly.This review is dedicated to summarizing the preparation methods and applications of IMLCs,emphasizing the advantages of them in the fields of energy storage,catalysis,sensors,electromagnetic interference(EMI)shielding and biomedicine.Furthermore,prospects and further developments in these gratifying fields are also commented.
基金supported by the National Natural Science Foundation of China(Nos.11002026 and 11372039)Beijing Natural Science Foundation(No.3133039)the Scientific Research Foundation for the Returned(No.20121832001)
文摘The interaction of anti-plane elastic SH waves with a periodic array of interface cracks in a multi-layered periodic medium is analyzed in this paper. A perfect periodic structure without interface cracks is first studied and the transmission displacement coefficient is obtained based on the transfer matrix method in conjunction with the Bloch-Floquet theorem. This is then generalized to a single and periodic distribution of cracks at the center interface and the result is compared with that of perfect periodic cases without interface cracks. The dependence of the transmission displacement coefficient on the frequency of the incident wave, the influences of material combination, crack configuration and incident angle are discussed in detail. Compared with the corresponding perfect periodic structure without interface cracks, a new phenomenon is found in the periodic layered system with a single and periodic array of interface cracks.
文摘A357-SiCp/A357 layered composites were prepared using a semi-solid vacuum stirring suction casting method.The microstructures,mechanical properties,and thermal conductivities of the composites fabricated under different suction casting processes were compared.Additionally,the microstructural evolution characteristics and performance enhancement mechanism of the A357-SiCp/A357 layered composites were discussed.The results demonstrate that suction casting at 610°C with a low solid phase ratio can significantly enhance the material density and reduce the agglomeration of SiCp.The A357-SiC_(p)/A357 interface is clear and straight with good bonding.With an increase in the suction casting temperature,the bending resistance and thermal conductivity of the A357-SiC_(p)/A357 layered composites exhibit a trend of significantly increase at first and then slowly decrease owing to casting defects,interface bonding,and SiCp distribution.Compared with SiCp/A357 composites,the bending strength,deflection,and thermal conductivity of the A357-SiCp/A357 layered composites increase from 257 MPa,1.07 mm,and 155.72 W·(m·K)^(-1) to 298 MPa,2.1 mm,and 169.86 W·(m·K)^(-1),respectively.This study provides a reference for improving the rheological casting of aluminum matrix layered composites.
基金supported by the Beijing Nova Program(No.Z141103001814006)the National Key Technology R&D Program(Nos.2012BAC12B05 and 2012BAC02B01)+1 种基金the National Natural Science Foundation of China(Nos.51174247 and U1360202)the National High-Tech Research and the Development Program of China(No.2012AA063202)
文摘The effect of height on performance of the PZT/Ni cylindrical bilayered magnetoelectric （ME） com- posites was studied in situ in this paper. Multiple resonant peaks appear between 1 and 300 kHz frequency for cyl- inders of different heights. The first resonance frequency does not change with the cylinder height decreasing, but the second and the third resonant frequencies increase. The first three resonant modes radial, first-order height are attributed to the cylinder resonance, and second-order height resonance, respectively. The appropriate size and resonance frequency were chosen to obtain the highest ME voltage coefficient when designing cylindrical bilayered magnetoelectric devices. This article provides reference to design cylindrical magnetoelectric devices.
基金This study was supported by Scientific and Technological Research Council of Turkey(TUBITAK)under the Grant Number 121S624.
文摘Total resection of glioblastoma(GB)tumors is nearly impossible,and systemic administration of temozolomide(TMZ)is often inadequate.This study presents a hybrid layered composite nanofiber network(LHN)designed for localized treatment in GB tumor bed.The LHN,consisting of polyvinyl alcohol and core-shell polylactic acid layers,was loaded with TMZ and rutin.In vitro analysis revealed that LHN^(TMZ) and LHNrutin decelerated epithelial-mesenchymal transition and growth of stem-like cells,while the combination,LHN^(TMZ)+rutin,significantly reduced sphere size compared to untreated and LHNTMZ-treated cells(P<0.0001).In an orthotopic C6-induced GB rat model,LHNTMZ+rutin therapy demonstrated a more pronounced tumor-reducing effect than LHNTMZ alone.Tumor volume,assessed by magnetic resonance imaging,was significantly reduced in LHN^(TMZ)+rutin-treated rats compared to untreated controls.Structural changes in tumor mitochondria,reduced membrane potential,and decreased PARP expression indicated the activation of apoptotic pathways in tumor cells,which was further confirmed by a reduction in PHH3,indicating decreased mitotic activity of tumor cells.Additionally,the local application of LHNs in the GB model mitigated aggressive tumor features without causing local tissue inflammation or adverse systemic effects.This was evidenced by a decrease in the angiogenesismarker CD31,the absence of inflammation or necrosis in H&E staining of the cerebellum,increased production of IFN-γ,decreased levels of interleukin-4 in splenic T cells,and lower serum AST levels.Our findings collectively indicate that LHN^(TMZ)+rutin is a promising biocompatible model for the local treatment of GB.
文摘The effects of a magnesium-based layered composite on the flammability of a phenolic epoxy resin(EP)are studied.In order to produce the required composite material,first,magnesium hydroxide,aluminum salt and deionized water are mixed into a reactor according to a certain proportion to induce a hydrothermal reaction;then,the feed liquid is filtered out using a solid-liquid separation procedure;finally,the material is dried and crushed.In order to evaluate its effects on the flammability of the EP,first,m-phenylenediamine is added to EP and vacuum defoamation is performed;then,EP is poured into a polytetrafluoroethylene mold,cooled to room temperature and demoulded;finally,the magnesium-based layered composite is added to EP,and its flame retardance is characterized by thermogravimetric analysis,limiting oxygen index and cone calorimetry.The X-ray diffraction patterns show that the baseline of magnesium-based layered composite is stable and the front shape is sharp and symmetrical when the molar ratio of magnesium to aluminium is 3.2:1;with the addition of magnesium-based layered composite,the initial pyrolysis temperature of EP of 10%,15%and 30%magnesium-based layered composite decreases to 318.2°C,317.9°C and 357.1°C,respectively.After the reaction,the amount of residual carbon increases to 0.1%,3.45%and 8.3%,and the limiting oxygen index increases by 28.3%,29.1%and 29.6%,respectively.The maximum heat release rate of cone calorimeter decreases gradually.The optimum molar ratio of Mg:Al for green synthesis is 3.2:1,and the NO_(3)-intercalated magnesium-based layered composite has the best flame retardance properties.
基金financially supported by the National Natural Science Foundation of China-Distinguished Young Scholars(No.52325407)the National Natural Science Foundation of China(No.52474401)+2 种基金the China Postdoctoral Science Foundation(No.2022M712919)the Guangdong Basic and Applied Basic Research Foundation(Nos.2023A1515140124 and 2025A1515012873)the Henan Province Science and Technology Research and Development Joint Fund(No.225200810013).
文摘Ag-based braze alloy has emerged as a promising filler for the fabrication of key components through joining between dissimilar materials,including but not limited to metals,ceramic,glass,graphite,diamond and C/C composite.A tremendous effort has been employed to develop new types of Ag-based braze alloy and composite braze alloy with desirable properties.However,the continuous emergence of new materials,extreme complexity of brazing structure and extreme severity of service environment continuously addresses new challenges for the new materials under extreme conditions,including the poor wettability,excessive brittle phase,high residual stress and deteriorated property of brazed joints,hindering the development of key components.This review is anticipated to deliver new guidelines for the design and utilization of Ag-based braze alloy and composite braze alloy toward the practical application in brazing with a desirable performance.Additionally,perspectives on future Ag-based braze alloy development are discussed.
基金supported by the Guangdong Basic and Applied Basic Research Foundation (2020B1515120013,2022B1515120066)National Natural Science Foundation of China (Nos.U2001218, 51875215)+1 种基金Key-Area Research and Development Program of Guangdong Province (2020B090923001)Special Support Foundation of Guangdong Province (No.2019TQ05Z110)。
文摘It has always been challenging work to reconcile the contradiction between the strength and plasticity of titanium materials.Laser powder bed fusion(LPBF) is a convenient method to fabricate innovative composites including those inspired by gradient layered materials.In this work,we used LPBF to selectively prepare Ti N/Ti gradient layered structure(GLSTi)composites by using different N_(2)–Ar ratios during the LPBF process.We systematically investigated the mechanisms of in-situ synthesis Ti N,high strength and ductility of GLSTi composites using microscopic analysis,TEM characterization,and tensile testing with digital image correlation.Besides,a digital correspondence was established between the N_(2) concentration and the volume fraction of LPBF in-situ synthesized Ti N.Our results show that the GLSTi composites exhibit superior mechanical properties compared to pure titanium fabricated by LPBF under pure Ar.Specifically,the tensile strength of GLSTi was more than 1.5times higher than that of LPBF-formed pure titanium,reaching up to 1100 MPa,while maintaining a high elongation at fracture of 17%.GLSTi breaks the bottleneck of high strength but low ductility exhibited by conventional nanoceramic particle-strengthened titanium matrix composites,and the hetero-deformation induced strengthening effect formed by the Ti N/Ti layered structure explained its strength-plasticity balanced principle.The microhardness exhibits a jagged variation of the relatively low hardness of 245 HV0.2 for the pure titanium layer and a high hardness of 408 HV0.2 for the N_(2) in-situ synthesis layer.Our study provides a new concept for the structure-performance digital customization of 3D-printed Ti-based composites.
基金Engineering Research Institute of Peking University (ERIPKU) Joint Building Project of Beijing Education Committee
文摘Theoretical analysis and numerical calculations of Love wave propagation in layered graded composites with imperfectly bonded interface are described in this paper. On the basis of WKB method, the approximate analytic solutions for Love waves are obtained. By the interface shear spring model, the dispersion relations for Love waves in layered graded composite structures with rigid, slip, and imperfectly bonded interfaces are given, and the effects of the interface conditions on the phase velocities of Love waves in SiC/Al layered graded composites are discussed. Numerical analysis shows that the phase velocity decreases when the defined flexibility parameter is greater. For the general imperfectly bonded interface, the phase velocity changes in the range of the velocities for the rigid and slip interface conditions.
基金financially supported by the National Natural Science Foundation of China(No.21376276)the Specialfunded Program on National Key Scientific Instruments and Equipment Development of China(No.2012YQ230043)+1 种基金Guangdong Province Sci&Tech Bureau(Key Strategic Project No.2008A080800024)the Fundamental Research Funds for the Central Universities
文摘Relatively well crystallized and high aspect ratio Mg-Al layered double hydroxides（LDHs） were prepared by coprecipitation process in aqueous solution and further rehydrated to an organic modified LDH（OLDH） in the presence of surfactant. The intercalated structure and high aspect ratio of OLDH were verified by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. A series of poly（propylene carbonate）（PPC）/OLDH composite films with different contents of OLDH were prepared via a melt-blending method. Their cross section morphologies, gas barrier properties and tensile strength were investigated as a function of OLDH contents. SEM results show that OLDH platelets are well dispersed within the composites and oriented parallel to the composite sheet plane. The gas barrier properties and tensile strength are obviously enhanced upon the incorporation of OLDH. Particularly, PPC/2%OLDH film exhibits the best barrier properties among all the composite films. Compared with pure PPC, the oxygen permeability coefficient（OP） and water vapor permeability coefficient（WVP） is reduced by 54% and 17% respectively with 2% OLDH addition. Furthermore, the tensile strength of PPC/2%OLDH is 83% higher than that of pure PPC with only small lose of elongation at break. Therefore, PPC/OLDH composite films show great potential application in packaging materials due to its biodegradable properties, superior oxygen and moisture barrier characteristics.
文摘Methods: 80 patients with anterior teeth defect (80 teeth) were selected from June 2018 to June 2020. The patients were randomly divided into two groups, 40 patients in each group (40 teeth). The control group was treated with conventional composite resin, while the observation group was treated with aesthetic composite resin layered plasticization. The success rate, satisfaction score, periodontal health status, pink aesthetic index (PES) score and complications occurred. Results: the success rate of repair in the observation group was higher than that in the control group (95%vs75%) (χ26.275, P 0.012 < 0.05). the satisfaction scores at the completion of repair and 3 months after repair were higher than those in the control group (P < 0.05). Three months after restoration, the number of periodontal health related indicators in the observation group was lower than that in the control group (P < 0.05). There was no significant difference in PES scores between the two groups before treatment (P > 0.05). The PES scores of the two groups were significantly higher at 12 and 24 months after treatment than before treatment (P < 0.05). The PES scores of the observation group were higher than those of the control group at 12 and 24 months after treatment (P < 0.05). After 2 years of follow-up, the observation group had complications such as prosthesis cutting, prosthesis discoloration, exogenous coloring, tooth sensitivity, while the control group had complications such as filling loss, pulpitis, dental caries, prosthesis discoloration, exogenous coloring, etc. The incidence of complications in the observation group (20%vs25%) was lower than that in the control group, but the difference was not statistically significant (P > 0.05). Conclusion: the aesthetic composite resin layered plasticizing technique has the advantages of high success rate, high satisfaction and good periodontal health. It is superior to the conventional composite resin restoration technique and is worthy of clinical promotion.
文摘Aseries of [(Fe_(0.6)Co_(0.2)Ni_(0.2))_(0.75-0.03x)B_(0.2)Si_(0.05+0.03x)]_(96)Nb_(4) amorphous alloy composite coatings were prepared by adjusting the silicon content(x=0,1,2,3,4,5,and 6)and their microstructures and tribological properties were investigated by laser cladding technique.Additionally,the effect of Si on the glass forming ability(GFA)of the layers was understood.Results show that an appropriate Si content can refine the microstructure of the FeCoNiBSiNb laser cladding layers and improve the mechanical and tribological properties.The hardness of the coating layer increases monotonically with the Si content.At the Si content of 4.8at%(x=0),the coating layer exhibits a relatively low hardness(734.2HV 0.1).Conversely,at the silicon content of 13.44at%(x=3),the coating layer exhibits the highest hardness(1106HV 0.1).The non-crystalline content and tensile strength exhibit an initial increase,followed by a subsequent decrease.At x=2,the coating exhibits its maximum fracture strength(2880 MPa).However,when x>2,the fracture strength of the coating decreases with an increase in x.Conversely,with an increase in Si content,the wear volume loss initially decreases and then increases.At a Si content of 10.56at%(x=2),the coating exhibits the highest non-crystalline content(42%),the highest tensile strength(2880 MPa),and the most favorable dry friction performance.
文摘Because of an unfortunate mistake during the production of this article,the Acknowledgements have been omitted.The Acknowledgements are added as follows:Sasan YAZDANI would like to thank the Scientific and Technological Research Council of Turkey(TÜB˙ITAK)for receiving financial support for this work through the 2221 Fellowship Program for Visiting Scientists and Scientists on Sabbatical Leave(Grant ID:E 21514107-115.02-228864).Sasan YAZDANI also expresses his gratitude to Sahand University of Technology for granting him sabbatical leave to facilitate the completion of this research.
基金supported by the National Natural Science Foundation of China(52161007)Science and Technology Planning Project of Guangdong Province of China(20170902,20180902)+1 种基金Science and Technology Planning Project of Yangjiang City of Guangdong Province(SDZX2020009)Research project of Shenzhen city(JSGG20210420091802007).
文摘In order to enhance the wear resistance of 45 steel,a WC/Stellite 6 composite layer with 30%WC which with different morphologies(spherical and irregular)was prepared on the surface of 45 steel by laser cladding technology.The effects of WC morphology on the phase composition,microstructure,microhardness,and wear resistance of the cladding layer were compared and analyzed.The res-ults show that the surface of the cladding layer was well formed.M_(23)C_(6),M_(7)C_(3),WC,and W_(2)C exist in both cladding layers.With the ad-dition of spherical WC,the diffraction peaks of γ-Co appear on the left side of the main peak of Co6W6C.The area of intergranular carbides accounts for a large proportion in the surface layer which with the fine grains.During the process of laser cladding the spherical WC particles with loose structure are prone to melting,including their interior.However,the melting amount of irregular WC particles is finite,which only occurs on the periphery of the particles,and the particle interior is relatively intact.The microhard-ness of two cladding layers gradient increases from the substrate to the surface layer.The surface layer added spherical WC has high-er microhardness,which reaches 790.6 HV1.Nevertheless,the wear resistance of the cladding layer added irregular WC is better than that of the cladding layer added spherical WC.The reason is because that the incompletely melted irregular WC particles are uni-formly distributed in the cladding layer which provided the support points for the cladding layer matrix during the wear process,the wear of the cladding layer by the grinding pair is reduced consequently.
基金financially supported by National Natural Science Foundation of China(22202124 and UA22A20429)Shanxi Scholarship Council of China(2023-008 and 2023-009)+4 种基金Shanxi Outstanding Project Selection and Support Program for Overseas Scientific and Technological Activities(20230002)Science and Technology Innovation Teams of Shanxi Province(202304051001023)the Key Research and Development Program of Shanxi Province(No.202302060301009)Qingdao New Energy Shandong Laboratory Open Project(QNESL OP)Shandong Provincial Natural Science Foundation(Nos.ZR2024QB175 and ZR2023LFG005).
文摘This study introduces an innovative composite cathode catalyst layer(CCL)design for proton exchange membrane fuel cells(PEMFCs),combining Pt-supported by Vulcan carbon(Pt/V)and Ketjenblack carbon(Pt/KB)to overcome mass transport limitations and ionomer-induced catalyst poisoning.The composite architecture strategically positions Pt/V layer with lower ionomer-to-carbon ratio(I/C=0.6)near the proton exchange membrane to maximize surface Pt accessibility and oxygen transport efficiency,whereas Pt/KB layer(I/C=0.9)adjacent to the gas diffusion layer leverages its porous structure to shield Pt from sulfonate group poisoning and enhance proton conduction under low-humidity conditions.This synergistic carbon support engineering achieves a balance between reactant accessibility and catalyst utilization,as demonstrated by improved power density,reduced transport resistance,and higher Pt utilization under dry conditions.These findings establish a new paradigm for low-Pt CCL design through rational carbon support hybridization and ionomer gradient engineering,offering a scalable solution for high-performance PEMFCs in energy-critical applications.
基金Projects(51071070,51271079)supported by the National Natural Science Foundation of ChinaProject(NCET-11-0156)supported by New Century Excellent Talents in University,China
文摘Large area diamond films were fabricated on copper substrates by a multi-step process comprised of electroplating Cu-diamond composite layer on Cu substrate, plating a Cu layer to fix the protruding diamond particles, and depositing continuous diamond film on composite interlayer by hot-filament chemical vapor deposition （HFCVD）. The interface characteristics, internal stress and adhesion strength were investigated by scanning electron microscopy, Raman analysis and indentation test. The results show that the continuous film without cracks is successfully obtained. The microstructure of the film is a mixture of large cubo-octahedron grains grown from homo-epitaxial growth and small grains with （111） apparent facets grown from lateral second nuclei. The improved adhesion between diamond film and substrate results from the deep anchoring of the diamond particles in the Cu matrix and the low residual stress in the film.
基金financially supported by the Russian Science Foundation(No.17-72-10042)
文摘A three-dimensional plasticity model was developed and applied to metal-intermetallic laminate composites containingphases of the L12 structure. A multi-scale approach that combined the methods of continuum mechanics and dislocationkinetics was used. This model takes account of the different mechanisms of self-locking superdislocations, the dislocationsand the dislocation walls＇ density storage for each type of layer at the micro-scale. At the meso-scale, the solutions to thedislocation kinetics equations, in the form of stress-strain curves, were used to create the properties of a three-dimensionalrepresentative element. The numerical simulation study of the macroscopic deformation was carried out with the finiteelement method using the dynamic model of continuum mechanics, which included the classical conservation laws,constitutive equations and the equation of state. It was shown that the simulation results generated using this model were ingood agreement with the mechanical tests conducted on the single crystals of the L12 structure. The model provides anexcellent description of the high-temperature plastic strain superlocalization effect of single crystal intermetallics of theLI2 structure. This paper describes the numerical results of the study of the tension and compression tests of metal-intermetallic laminate composites containing phases of the L12 structure. The model allows the description of the dis-tribution of the accumulated plastic strain inhomogeneities and is capable of predicting the strengthening properties andplastic behaviour of the metal-intermetallic laminate composites containing phases of the L12 structure.
基金Supported by the National Basic Research Program of China("973" Program)(613135)
文摘A concave die with an equal-strain contour line was used in the hydrostatic extrusion process to deform the two-layer Cu/A1 composite. The extruding process was simulated using the fi- nite element method （FEM）. The effect of the friction coefficients on the relative slippage of the contact surfaces between the internal and external metals was investigated, and the stress distribu- tion in the extruded specimen was studied. The simulation results reveal that the relative slippage de- creases with increasing friction coefficient at the contact surface of the two metals. However, the relative slippage increases rapidly with increasing friction coefficient at the contact surface between the specimen and die. No axial tensile stress appears in the plastic deformation zone near the axis, indicating that the inner fracture will not occur in internal metal in the hydrostatic extrusion process as the concave die with equal-strain contour lines is used. The experimental test reveals that the met- allurgical bond is formed between Cu and A1 when the friction coefficient at the surface between the two metals is 0. 3 and the extrusion ratio is 12.
基金financially supported by the National Natural Science Foundation of China Project under grant No.51371090the Science and Technology Support Program of 12th Five-Year Plan under grant No.2011BAD20B03010401+4 种基金the Educational Department Surface Project of Heilongjiang Province under grant No.12521519the Cultivation Plan of the New Century Excellent Talents of Heilongjiang Province under grant No.1155-NCET-017the College Student Science and Technology Innovation of Heilongjiang Province under grant No.201410222037the College Student Science and Technology Innovation of Jiamusi University under grant No.xsld2014-002Graduate Student Science and Technology Innovation of Jiamusi University LZR2014_007
文摘A low carbon steel （LCS）/high chromium white cast iron （HCCI） bimetal wear plate about 20 mm in thickness was prepared by liquid-liquid bimetal composite casting technology to substitute for the welding wear plate. A clear and distinguishable composite layer between the LCS and the HCCI was detected with SEM, and the composition and phase were analyzed through EDS and XRD. The composite layer was composed of three sublayers from the LCS to the HCCI： pearlite transition layer, composite layer, and HCCI transition layer. The Vickers hardness from the pearlite transition layer to the HCCl transition layer was 360 HV to 855 HV. The austenite grows as dendrites between the composite layer and the HCCI transition layer under constitutional undercooling. A large amount of C and Cr, and a small amount of Si and Mn dissolve in the matrix. Granular Cr7C3 is uniformly distributed. Due to the solute redistribution at the solid-liquid interface, the primary austenite grows from planar to cellular and finally to the distinct dendrite crystals. The dendrite crystals have an obvious growth direction perpendicular to the composite layer.
基金Funded by"Xi-Bu-Zhi-Guang" Foundation of Chinese Academy of Sciences(No.XBZG-2007-5)Gansu Natural Science Foundation of China(No.0806RJYA004)Outstanding Youngth of Lanzhou University of Technology (No.Q200910)
文摘The surface infiltrated composite （Ni/WC） layers on gray iron substrate were fabricated through a vacuum infiltration casting technique （VICT） using Ni-based composite powder with different WC particles content as raw materials.The microstructures of surface infiltrated composite layer,the interface structures between surface composite layer and the substrate,the changes of macro-hardness with the increasing of WC content and the micro-hardness distribution are investigated.The infiltrated composite layer includes a surface composite layer and a transition layer,and the thickness of the transition layer decreases with the increasing content of WC.The thickness of transition layer with 20%WC content in the surface infiltrated composite layer was 170 μm which was the thickest for all transition layers with different WC content.The surface composite layer was mainly composed of WC,W2C,FeB and NiB,along with Ni-Cr-Fe,Ni （Cr） solid solution,Ni （Si） solid solution and Ni （Fe） solid solution.The transition layer was composed of Ni （Cr） solid solution,Ni （Fe） solid solution,Ni （Si） solid solution,Fe （Ni） solid solution and eutectic.The surface macro-hardness and micro-hardness of the infiltrated layer had been evaluated.The macro-hardness of the surface composite layer decreases with the WC content increasing,and the average macro-hardness is HRC60.The distribution of micro-hardness presents gradient change.The average micro-hardness of the infiltrated layer is about HV1000.
