The Fe_(949.7)Cr_(18)Mn_(1.9)Mo_(7.4)W_(1.6)B_(15.2)C_(3.8)Si_(2) amorphous coating was deposited on T91 steel substrate by using the high-velocity oxygen fuel(HVOF)spray technique to enhance the corrosion resistance ...The Fe_(949.7)Cr_(18)Mn_(1.9)Mo_(7.4)W_(1.6)B_(15.2)C_(3.8)Si_(2) amorphous coating was deposited on T91 steel substrate by using the high-velocity oxygen fuel(HVOF)spray technique to enhance the corrosion resistance of T91 stainless steel in liquid lead-bismuth eutectic(LBE).The corrosion behavior of the T91 steel and coating exposed to oxygen-saturated LBE at 400℃ for 500 h was investigated.Results showed that the T91 substrate was severely corroded and covered by a homogeneously distributed dual-layer oxide on the interface contacted to LBE,consisting of an outer magnetite layer and an inner Fe-Cr spinel layer.Meanwhile,the amorphous coating with a high glass transition temperature(Tg=550℃)and crystallization temperature(T_(x)=600℃)exhibited dramatically enhanced thermal stability and corrosion resistance.No visible LBE penetration was observed,although small amounts of Fe_(3)O_(4),Cr_(2)O_(3),and PbO were found on the coating surface.In addition,the amorphicity and interface bonding of the coating layer remained unchanged after the LBE corrosion.The Fe-based amorphous coating can act as a stable barrier layer in liquid LBE and have great application potential for long-term service in LBE-cooled fast reactors.展开更多
Fe-based powder with a composition of Fe_（42.87）Cr_（15.98）Mo_（16.33）C_（15.94）B_（8.88）（at.%）was used to fabricate coatings by high-velocity oxygen fuel spraying.The effects of the spraying parameters on the...Fe-based powder with a composition of Fe_（42.87）Cr_（15.98）Mo_（16.33）C_（15.94）B_（8.88）（at.%）was used to fabricate coatings by high-velocity oxygen fuel spraying.The effects of the spraying parameters on the microstructure and the wear properties of the Fe-based alloy coatings were systematically studied.The results showed that the obtained Fe-based coatings with a thickness of about 400μm consisted of a large-volume amorphous phase and some nanocrystals.With increasing the fuel and oxygen flow rates,the porosity of the obtained coatings decreased.The coating deposited under optimized parameters exhibited the lowest porosity of 2.8%.The excellent wear resistance of this coating was attributed to the properties of the amorphous matrix and the presence of nanocrystals homogeneously distributed within the matrix.The wear mechanism of the coatings was discussed on the basis of observations of the worn surfaces.展开更多
Amorphous alloys without crystalline defects(dislocation,crystal boundary)are ideal hydrophobic coating materials due to their low surface energy.This work used a synergistic method of detonation spraying and surface ...Amorphous alloys without crystalline defects(dislocation,crystal boundary)are ideal hydrophobic coating materials due to their low surface energy.This work used a synergistic method of detonation spraying and surface modification to obtain the superhydrophobic Febased amorphous coatings with high hardness and dense structure on the Q 235 substrate.The results showed that the water contact angles(WCA)of the superhydrophobic coating was 160°±3.6°,and water droplets could bounce off the superhydrophobic coating surface,illustrating the excellent self-cleaning performance of coating.Notably,the corrosion current density(i_(corr))of the superhydrophobic coating further decreased by 2 orders of magnitude down to8.008×10^(-8)A·cm^(-2)compared to the as-deposited coating with 5.473×10^(-6)A·cm^(-2);the corrosion potential(E_(corr))of the superhydrophobic coating shifted by 34 mV to the positive side compared with that of the as-deposited coating(-310 mV).Likewise,the impedance modulus|Z|values of the superhydrophobic coating increased by nearly2 orders of magnitude up to 1×10^(5.6)compared to the asdeposited coating with 1×10^(3.8).Even through lasting immersion in NaCl for 10 days,|Z|values of the superhydrophobic coating were still much higher than those of the as-deposited coating.The superhydrophobic Fe-based amorphous coatings could respond to their applications under extreme conditions due to their excellent hydrophobicity and self-cleaning properties,illustrating their promising future in aerospace,automotive,and machinery industries.展开更多
Hot corrosion behaviors of the 921A alloy and Fe-based amorphous coating induced by KCl-10% ZnCl_(2) and KCl-55% ZnCl_(2) salts at 450℃ in air for 40 h were investigated.Results show that the 921A alloy suffers more ...Hot corrosion behaviors of the 921A alloy and Fe-based amorphous coating induced by KCl-10% ZnCl_(2) and KCl-55% ZnCl_(2) salts at 450℃ in air for 40 h were investigated.Results show that the 921A alloy suffers more serious corrosion damage than the coating and KCl-55% ZnCl_(2) salts are more corrosive than KCl-10% ZnCl_(2) salts.In the two salts,an Fe_(2)O_(3) layer is formed on the 921A alloy surface,while an outer Fe-rich oxide layer and an inner Cr-rich oxide layer are formed on the surface of the coating.Moreover,a certain amount of metal chloride can be found at the oxide/alloy(coating)interface,which can be explained by "active oxidation".However,the corrosion resistance of the Fe-based amorphous coating did not achieve the desired results,probably because the intersplats in the coating serve as corrosion diffusing channels,which facilitate the corrosion damage rate.Nevertheless,the coating is still in amorphous state after hot corrosion exposure.展开更多
The effects of kerosene flow rate on the microstructure and wearing properties were investigated for Fe-based amorphous coatings sprayed by High Velocity Oxygen Fuel (HVOF).The microstructures and wearing properties o...The effects of kerosene flow rate on the microstructure and wearing properties were investigated for Fe-based amorphous coatings sprayed by High Velocity Oxygen Fuel (HVOF).The microstructures and wearing properties of the Fe-based amorphous coatings were analyzed with scanning electron microscope (SEM),X-ray diffraction analyzer (XRD),and ball-on-disc tribometer (CFT-1),respectively.The experimental results show that the well interfacial bonding can be observed between the amorphous coating layer and the substrate,and the porosity in amorphous coating layer is less to 1%.Only some crystalline a-Fe and FeO phases can be detected by XRD in the amorphous coatings,while the amorphous content is up to 99.4%.The wearing coefficient is near to 0.15,which is superior to SUS316 of 0.28.As the increasing of wearing loads,the failure mode is changed from oxidation wear to the composite of oxidation and abrasive wear.展开更多
This study investigated the effect of annealing below glass transition temperature(T_(g))on the microstructural characteristics,mechanical property,wettability,and electrochemical performance of activated combustion-h...This study investigated the effect of annealing below glass transition temperature(T_(g))on the microstructural characteristics,mechanical property,wettability,and electrochemical performance of activated combustion-high velocity air fuel(AC-HVAF)-sprayed Fe-Cr-Mo-W-C-B-Y amorphous coatings(ACs).Results showed that Fe-based ACs with a thickness of~300μm exhibited a fully amorphous structure with low oxidization.Originating from the reduced free volume,sub-T_(g) annealing increased the thermal stability,hardness,and surface hydrophobicity of Fe-based ACs.The enhanced corrosion resistance of sub-T_(g) annealed ACs in 3.5 wt%NaCl solution was attributed to the increased surface hydrophobicity and passivation capability.This finding elucidates the correlation between sub-T_(g) annealing and the properties of Fe-based ACs,which promotes ameliorating ACs with superior performance.展开更多
The effects of deep cryogenic-cycling treatment(DCT)on the mechanical properties,soft magnetic properties,and atomic scale structure of the Fe_(73.5)Si_(13.5)B_(9)Nb_(3)Cu_(1)amorphous nanocrystalline alloy were inves...The effects of deep cryogenic-cycling treatment(DCT)on the mechanical properties,soft magnetic properties,and atomic scale structure of the Fe_(73.5)Si_(13.5)B_(9)Nb_(3)Cu_(1)amorphous nanocrystalline alloy were investigated.The DCT samples were obtained by subjecting the as-annealed samples to a thermal cycling process between the temperature of the supercooled liquid zone and the temperature of liquid nitrogen.Through flat plate bending testing,hardness measurements,and nanoindentation experiment,it is found that the bending toughness of the DCT samples is improved and the soft magnetic properties are also slightly enhanced.These are attributed to the rejuvenation behavior of the DCT samples,which demonstrate a higher enthalpy of relaxation.Therefore,DCT is an effective method to enhance the bending toughness of Fe-based amorphous nanocrystalline alloys without degrading the soft magnetic properties.展开更多
Achieving a delicate synergy between mechanical robustness and antifouling attributes in coatings remains a formidable challenge for marine applications. Inspired by the assembly of nacre, we present a novel approach ...Achieving a delicate synergy between mechanical robustness and antifouling attributes in coatings remains a formidable challenge for marine applications. Inspired by the assembly of nacre, we present a novel approach to fabricate a nacre-like metallic coating. This coating comprises an amorphous matrix with excellent anti-corrosion and anti-wear properties, as well as Cu-rich 3D interconnected channels for antifouling function. The coating is produced by high velocity oxygen fuel (HVOF) thermal spraying of surface-modified Fe-based amorphous powders with a Cu-layer. The resulting coating exhibits exceptional mechanical robustness, including high resistance to erosion, abrasion, and impact, surpassing conventional polymer antifouling coatings. Furthermore, the controlled Cu+ leaching capability of the in-situ constructed 3D interconnected diffusion channels, facilitated by the Cu-rich intersplats, contributes to the remarkable antifouling performance. This includes nearly 100 % resistance to bacterial adhesion after 1 day of immersion and over 98 % resistance to algal attachment after 7 d of immersion, resulting in a prolonged service lifetime. Notably, even after 200 cycles of wear damage, the Cu-modified amorphous coating still maintains its excellent antifouling properties. The Cu-rich intersplats play a critical role in transporting and sustainably leaching Cu ions, thereby accounting for the outstanding antifouling performance. Ultimately, we aim to advance the design of high-performance coatings suited for diverse marine applications, where both the mechanical robustness and antifouling properties are essential.展开更多
The Fe-based amorphous metallic matrix coating （Fe-AMMC） was fabricated with the powder mixtures of Fe-based metallic glass synthesized with industrial raw materials, NiCr alloy and WC particle by high velocity oxy-...The Fe-based amorphous metallic matrix coating （Fe-AMMC） was fabricated with the powder mixtures of Fe-based metallic glass synthesized with industrial raw materials, NiCr alloy and WC particle by high velocity oxy-fuel （HVOF） spraying. The corrosion resistance of Fe-AMMC was investigated by potentiodynamic polarization tests in 1 mol/L HCl, NaCl, H2SO4 and NaOH solutions, respectively. The surface morphologies corroded were observed by SEM. The results indicate that Fe-AMMC exhibits excellent corrosion resistance, higher corrosion resistance than 304L stainless steel in the chloride solutions. The low corrosion current density and passive current density of Fe-AMMC with a wide spontaneous passivation region are about 132.0μA/cm2 and 9.0 mA/cm2 in HCl solution, and about 2.5 μA/cm2 and 2.3 mA/cm2 in NaCl solution. The excellent corrosion resistance demonstrates that Fe-based amorphous metallic matrix powder is a viable engineering material in practical anti-corrosion and anti-wear coating applications.展开更多
In this study,a few Fe-based amorphous matrix composite coatings reinforced with various portions(4,8 and16 vol.%) of 31 6L stainless steel powders have been successfully produced through high velocity oxy-fuel(HVOF) ...In this study,a few Fe-based amorphous matrix composite coatings reinforced with various portions(4,8 and16 vol.%) of 31 6L stainless steel powders have been successfully produced through high velocity oxy-fuel(HVOF) spraying.The microstructure of the composite coatings was systematically characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The main structure of composite coatings remained amorphous while 31 6L stainless steel splats were distributed homogeneously in the amorphous matrix and well connected with surrounding amorphous phase.Bonding strength of coatings to the substrate was determined by 'pull-off' tensile tests.The results revealed that the31 6L stainless steel phase effectively improved the bonding strength of amorphous coatings,which is mainly contributed by the strong metallurgical bonding between stainless steel and amorphous splats.The addition of31 6L stainless steel also enhanced the ductility and fracture resistance of the coatings due to the ductile stainless steel phases,which can arrest crack propagation and increase energy dissipation.展开更多
Lead-bismuth eutectics (LBE) have considerable potential as a candidate material for accelerator-driven sub-critical systems(ADS).However,LBE corrosion and irradiation damage are two urgent challenges remaining to be ...Lead-bismuth eutectics (LBE) have considerable potential as a candidate material for accelerator-driven sub-critical systems(ADS).However,LBE corrosion and irradiation damage are two urgent challenges remaining to be solved for impellers of primary pumps.In this study,we have explored the possibility of using Fe-based amorphous coatings to overcome LBE corrosion and concurrently to sustain irradiation damage.Specifically,the Fe_(54)Cr_(18)Mo_(2)Zr_(8)B_(18)amorphous coating was prepared by high-velocity oxygen-fuel (HVOF) spraying on 316L steel and exposed to saturated oxygen static LBE for 500 h at 400℃.The coating with high thermal stability (T_(g)=615℃ and T_(x)=660℃) effectively prevented the substrate steel from being corroded by LBE owing to its unique long-range disordered atomic packing.The coating also exhibited strong irradiation resistance when being subjected to 45 dpa (displacement per atom) Au ion irradiation at room temperature,with no sign of crystallization even at the maximum implantation depth of 300 nm.Consequently,the hardness of the coatings before and after irradiation increased slightly.The current findings shed new insights into understanding corrosion mechanism and irradiation behavior of amorphous solids in LBE and expand the application range of amorphous materials.展开更多
Amorphous metallic coatings with a composition of Fe48Cr15Mo14C15B6Y2 were prepared by detonation gun spraying process. Microstructural studies show that the coatings present a densely layered structure typical of the...Amorphous metallic coatings with a composition of Fe48Cr15Mo14C15B6Y2 were prepared by detonation gun spraying process. Microstructural studies show that the coatings present a densely layered structure typical of thermally sprayed deposits with the porosity below 2%. Both crystallization and oxidation occurred obviously during spraying process, so that the amorphous fraction of the coatings decreased to 54% compared with fully amorphous alloy ribbons of the same component. Corrosion behavior of the amorphous coatings was investigated by electrochemical measurement. The results show that the coatings exhibit extremely wide passive region and low passive current density in 3.5% NaCl (mass fraction) and 1 mol/L HCl solutions, which illustrates excellent ability to resist localized corrosion.展开更多
Amorphous metallic coatings with a composition of Fe48Cr15Mo14C15B6Y2 were prepared by means of atmospheric plasma spraying (APS) process under different conditions. The microstructure and frictional behavior were cha...Amorphous metallic coatings with a composition of Fe48Cr15Mo14C15B6Y2 were prepared by means of atmospheric plasma spraying (APS) process under different conditions. The microstructure and frictional behavior were characterized simultaneously in this article. The results show that the as-deposited coatings consist of amorphous matrix and some precipitated nanocrystals, while the amorphous fraction and particle deformation as well as crystallization mechanism are significantly sensitive to the spraying parameters. The amorphous coatings express high microhardness and excellent wear resistance under dry frictional wear condition, which attributes to the inherent characteristic of amorphous phase and the dispersion strengthening of precipitated nanocrystals. The dominant wear mechanism of the amorphous coatings is fatigue wear accompanying with oxidative wear. In addition, the microhardness and wear resistance of the amorphous coatings were improved by optimizing spraying parameters, owing to the effect of both structural character and proper proportional of amorphous and nanocrystals fraction.展开更多
In this work,the electrochemical behaviors of SAM2X5 Fe-based amorphous alloy coating and hard chromium coating were comparatively studied in 3.5 wt% NaCl solution.In comparison with the hard chromium coating,the SAM2...In this work,the electrochemical behaviors of SAM2X5 Fe-based amorphous alloy coating and hard chromium coating were comparatively studied in 3.5 wt% NaCl solution.In comparison with the hard chromium coating,the SAM2X5 coating exhibited a wider and stable passive region with lower passive current density in the potentiodynamic polarization and showed a considerably lower current density at different anodic potentials in the potentiostatic polarization.In order to understand the passivation mechanism of the Fe-based amorphous coating,the components of the passive films formed at various polarization potentials were examined by X-ray photoelectron spectroscopy.The synergistic effect of Mo,W,Mn and Cr in the passive films was systemically analyzed.It has been revealed that Mo and W facilitate the formation of compact and stable Cr2O3 passive film at lower potentials,and the substantial enrichment of Mn in the passive film enhances the passivation ability at relatively higher potentials.The deep understanding of the passivation characteristics in multicomponent alloy systems could provide a guide for the design of corrosion-resistant amorphous alloy coatings for engineering applications.展开更多
Fe-based amorphous composite coatings were fabricated on AISI 1045 steel by laser cladding. The results of the X- ray diffraction and transmission electron microscopy analyses .show the coating is composed of an amorp...Fe-based amorphous composite coatings were fabricated on AISI 1045 steel by laser cladding. The results of the X- ray diffraction and transmission electron microscopy analyses .show the coating is composed of an amorphous phase in majority and a nanocrystaUine phuse in m,inority. Phase composition of the coating changes along the depth of the coating. The reasonable scanning speed for fabricating an amorphous composite coating is 3 500 mm/min when the laser power is 4 800 W and the laser beam diameter is 2 mm. If the scanning speed is lower than 3 500 mm/min, the intensity of the two main diffraction peaks in X-ray diffraction patterns of the coatings decreases with the scanning speeds increasing. At the same time, a broad halo peak emerges and enlarges. High laser power and fast scanning speed are the essential conditions of amorphization. The coating exhibits high microhardness.展开更多
(Zr_(0.53)Al_(0.1)Ni_(0.05)Cu_(0.3)Ti_(0.02))_(99)Y_1(at%)coating with amorphous layer of about 180μm thick was prepared on a steel substrate by using laser cladding method.The coating is compact and shows good metal...(Zr_(0.53)Al_(0.1)Ni_(0.05)Cu_(0.3)Ti_(0.02))_(99)Y_1(at%)coating with amorphous layer of about 180μm thick was prepared on a steel substrate by using laser cladding method.The coating is compact and shows good metallurgical bonding with substrate.The microstructure,microhardness and corrosion behavior along the depth from the coating surface to the substrate were investigated.It is found that a gradient structure consisted of amorphous surface layer,amorphous-crystalline transitional layer and substrate is formed after the laser cladding.The microhardness and corrosion behavior exhibit variation with the microstructural evolution at different depths from the coating surface.The microhardness and corrosion resistance in 3.5 wt%NaCl solution of the amorphous surface layer are comparable to those of the as-cast Zr-based BMG with the same composition,and higher than those of the steel substrate.展开更多
In this paper, alloy powders mixed with a molar ratio of Fe ： P ： C of 80 ： 13 ： 7 were sprayed on Q235 steel by plasma spray method to prepare coating with amorphous phases. The phase composition of the mixed all...In this paper, alloy powders mixed with a molar ratio of Fe ： P ： C of 80 ： 13 ： 7 were sprayed on Q235 steel by plasma spray method to prepare coating with amorphous phases. The phase composition of the mixed alloy powders and prepared coating were characterized by X-ray diffraction （ XRD ）. The morphology and the composition cf the coating were analyzed by scanning eleetron microscopy （SEM） nnd energy dispersive apectroscopy （ EDS ）. In addition, the thermal stability ef the coating with amorphous phases was characterized by differential thermal analyzer （ DTA ）. Tile results showed that, usirtg mixed alloy powders with a molar ratio of Fe： P： C of 80：13：7, the coating containing certain amount of amorphous alloys was suceessathlly prepared through atmospheric plasma spray technique. In the coating, the main phases were determined to be Fe, FeP aad Fe2P. The crystallization of the coating started from about 461°. Tile coating was mechanically adhered to the substrate.展开更多
Laser 3D printing,also known as laser additive manufacturing(LAM),is favored for its ability to form bulk metallic glass(BMG)and its composite materials(BMGcs)with freeform geometries.In this work,two different kinds ...Laser 3D printing,also known as laser additive manufacturing(LAM),is favored for its ability to form bulk metallic glass(BMG)and its composite materials(BMGcs)with freeform geometries.In this work,two different kinds of Fe_(41)Co_(7)Cr_(15)Mo_(14)C_(15)B_(6)Y_(2)amorphous coatings(A and B)were prepared by using LAM technology under air-and water-cooled conditions,respectively;meanwhile,to reduce the cracks generated due to the residual thermal stresses,coating C obtained by air-sweep annealing of B with a low energy-density laser.The morphology and amorphous content and microstructure of the coatings were investigated,the results show many cracks in coating B deposited under water-cooled conditions,and its microstructure shows an amorphous-crystal-nanocrystalline mixed structure.Cracking was suppressed in coating C,obtained by air-sweep annealing based on coating B,but the amorphous content was reduced from 32.6 to 13.4%.And the hardness and corrosion resistance of the coating will increase with the increase in the amorphous content.Finally,the internal friction behavior of a BMGcs was prepared on the basis of the process of sample C is compared with that of as-cast amorphous alloys.The results show that the low temperature internal friction behavior of BMGcs is affected by the defects produced during printing,and the high temperature internal friction behavior is affected by the precipitated hard phase.展开更多
A novel Fe–Cr–Mo amorphous coating,a high-temperature corrosion-resistant material for water wall protection of power plant ultra-supercritical boilers,has been prepared via arc spraying.A systematic study was condu...A novel Fe–Cr–Mo amorphous coating,a high-temperature corrosion-resistant material for water wall protection of power plant ultra-supercritical boilers,has been prepared via arc spraying.A systematic study was conducted to evaluate the high-temperature corrosion behavior of this coating,and its resistance to corrosion at high temperatures was scientifically assessed.The results indicate that the thickness of Fe–Cr–Mo amorphous coating is approximately 350μm,exhibiting typical amorphous characteristics as confirmed by X-ray diffraction and transmission electron microscope characterization.During each stage of the 750℃corrosion test,the oxygen content of the amorphous coating was significantly lower than that of the contrast coating(PS45 alloy coating),indicating a superior corrosion protection effect at high temperature.After 100 h of continuous testing,the corrosion mass gain of the amorphous coating was only 28.62%that of PS45 coating and 3.89%that of T12 steel substrate,indicating significantly depressed high-temperature corrosion kinetics.The excellent high-temperature corrosion resistance of Fe–Cr–Mo amorphous coating is primarily attributed to the stable Fe/Cr oxide film generated by the metastable state of the amorphous state,which serves as an excellent barrier.Furthermore,under the influence of heat in a high-temperature environment,the amorphous structure gradually transforms into a nanocrystalline structure.In contrast,the oxide film of the amorphous/nanocrystalline coating has low thermal stress,leading to better adhesion with the coating and resistance to cracking and peeling,thus providing excellent sustained protection.展开更多
Fe-based coating was produced on pure Ti substrate by the laser cladding technology. The composition and microstructure of the fabricated coating were analyzed by scanning electron microscopy （SEM）, X-ray diffracti...Fe-based coating was produced on pure Ti substrate by the laser cladding technology. The composition and microstructure of the fabricated coating were analyzed by scanning electron microscopy （SEM）, X-ray diffraction （XRD） and transmission electron microscopy （TEM） technique. The tribological properties were tested through sliding against AISI52100 steel ball at different normal loads and sliding speeds. Besides, the morphologies of the worn surfaces and wear debris were analyzed by scanning electron microscopy （SEM） and three dimensional （3D） non-contact surface mapping. The results show that the prepared Fe-based coating has a high hardness of about 860 HV0.2 and exhibits an average wear rate of （0.70-2.32）×10-6 mm3/（N-m）, showing that the Fe-based coating can greatly improve the wear resistance of pure Ti substrate. The wear mechanism of the coating involves moderate adhesive and abrasive wear.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 52061135207, 51871016, 51921001, 5197011039, 5197011018, and U20b200318)the China Nuclear Power Technology Research Institute Co., Ltd
文摘The Fe_(949.7)Cr_(18)Mn_(1.9)Mo_(7.4)W_(1.6)B_(15.2)C_(3.8)Si_(2) amorphous coating was deposited on T91 steel substrate by using the high-velocity oxygen fuel(HVOF)spray technique to enhance the corrosion resistance of T91 stainless steel in liquid lead-bismuth eutectic(LBE).The corrosion behavior of the T91 steel and coating exposed to oxygen-saturated LBE at 400℃ for 500 h was investigated.Results showed that the T91 substrate was severely corroded and covered by a homogeneously distributed dual-layer oxide on the interface contacted to LBE,consisting of an outer magnetite layer and an inner Fe-Cr spinel layer.Meanwhile,the amorphous coating with a high glass transition temperature(Tg=550℃)and crystallization temperature(T_(x)=600℃)exhibited dramatically enhanced thermal stability and corrosion resistance.No visible LBE penetration was observed,although small amounts of Fe_(3)O_(4),Cr_(2)O_(3),and PbO were found on the coating surface.In addition,the amorphicity and interface bonding of the coating layer remained unchanged after the LBE corrosion.The Fe-based amorphous coating can act as a stable barrier layer in liquid LBE and have great application potential for long-term service in LBE-cooled fast reactors.
基金Item Sponsored by National Natural Science Foundation of China(51205001)Key Project of Natural Science of Education Department of Anhui Province of China(KJ2014A023)Scientific Research Starting Foundation of Anhui Polytechnic University of China(2012YQQ006)
文摘Fe-based powder with a composition of Fe_（42.87）Cr_（15.98）Mo_（16.33）C_（15.94）B_（8.88）（at.%）was used to fabricate coatings by high-velocity oxygen fuel spraying.The effects of the spraying parameters on the microstructure and the wear properties of the Fe-based alloy coatings were systematically studied.The results showed that the obtained Fe-based coatings with a thickness of about 400μm consisted of a large-volume amorphous phase and some nanocrystals.With increasing the fuel and oxygen flow rates,the porosity of the obtained coatings decreased.The coating deposited under optimized parameters exhibited the lowest porosity of 2.8%.The excellent wear resistance of this coating was attributed to the properties of the amorphous matrix and the presence of nanocrystals homogeneously distributed within the matrix.The wear mechanism of the coatings was discussed on the basis of observations of the worn surfaces.
基金financially supported by the National Natural Science Foundation of China(Nos.51901092,52075234)the Program of"Science and Technology International Cooperation Demonstrative Base of Metal Surface Engineering along the Silk Road(No.2017D01003)"+3 种基金the"111"project(No.D21032)the Key Research Program of Education Department of Gansu Province(No.GSSYLXM-03)the Natural Science Foundation of Gansu Province(No.20JR5RA431)Hongliu Distinguished Young Talent Support Program of Lanzhou University of Technology,and the Open Fund Project of Hunan Province Key Laboratory of Electromagnetic Equipment Design and Manufacturing,Hunan Institute of Technology(No.DC202001)。
文摘Amorphous alloys without crystalline defects(dislocation,crystal boundary)are ideal hydrophobic coating materials due to their low surface energy.This work used a synergistic method of detonation spraying and surface modification to obtain the superhydrophobic Febased amorphous coatings with high hardness and dense structure on the Q 235 substrate.The results showed that the water contact angles(WCA)of the superhydrophobic coating was 160°±3.6°,and water droplets could bounce off the superhydrophobic coating surface,illustrating the excellent self-cleaning performance of coating.Notably,the corrosion current density(i_(corr))of the superhydrophobic coating further decreased by 2 orders of magnitude down to8.008×10^(-8)A·cm^(-2)compared to the as-deposited coating with 5.473×10^(-6)A·cm^(-2);the corrosion potential(E_(corr))of the superhydrophobic coating shifted by 34 mV to the positive side compared with that of the as-deposited coating(-310 mV).Likewise,the impedance modulus|Z|values of the superhydrophobic coating increased by nearly2 orders of magnitude up to 1×10^(5.6)compared to the asdeposited coating with 1×10^(3.8).Even through lasting immersion in NaCl for 10 days,|Z|values of the superhydrophobic coating were still much higher than those of the as-deposited coating.The superhydrophobic Fe-based amorphous coatings could respond to their applications under extreme conditions due to their excellent hydrophobicity and self-cleaning properties,illustrating their promising future in aerospace,automotive,and machinery industries.
基金supported by GuangDong Basic and Applied Basic Research Foundation(No.2020A1515110128).
文摘Hot corrosion behaviors of the 921A alloy and Fe-based amorphous coating induced by KCl-10% ZnCl_(2) and KCl-55% ZnCl_(2) salts at 450℃ in air for 40 h were investigated.Results show that the 921A alloy suffers more serious corrosion damage than the coating and KCl-55% ZnCl_(2) salts are more corrosive than KCl-10% ZnCl_(2) salts.In the two salts,an Fe_(2)O_(3) layer is formed on the 921A alloy surface,while an outer Fe-rich oxide layer and an inner Cr-rich oxide layer are formed on the surface of the coating.Moreover,a certain amount of metal chloride can be found at the oxide/alloy(coating)interface,which can be explained by "active oxidation".However,the corrosion resistance of the Fe-based amorphous coating did not achieve the desired results,probably because the intersplats in the coating serve as corrosion diffusing channels,which facilitate the corrosion damage rate.Nevertheless,the coating is still in amorphous state after hot corrosion exposure.
基金Funded by the National Natural Science Foundation of China(No.51965044)the Basic Pre Research of General Armament Department(No.41423060313)。
文摘The effects of kerosene flow rate on the microstructure and wearing properties were investigated for Fe-based amorphous coatings sprayed by High Velocity Oxygen Fuel (HVOF).The microstructures and wearing properties of the Fe-based amorphous coatings were analyzed with scanning electron microscope (SEM),X-ray diffraction analyzer (XRD),and ball-on-disc tribometer (CFT-1),respectively.The experimental results show that the well interfacial bonding can be observed between the amorphous coating layer and the substrate,and the porosity in amorphous coating layer is less to 1%.Only some crystalline a-Fe and FeO phases can be detected by XRD in the amorphous coatings,while the amorphous content is up to 99.4%.The wearing coefficient is near to 0.15,which is superior to SUS316 of 0.28.As the increasing of wearing loads,the failure mode is changed from oxidation wear to the composite of oxidation and abrasive wear.
基金supported by the National Natural Science Foundation of China(No.51901138)the Postdoctoral Science Foundation of China(No.2020M672788)the National Key Research and Development Program of China(No.2018YFA0703605)。
文摘This study investigated the effect of annealing below glass transition temperature(T_(g))on the microstructural characteristics,mechanical property,wettability,and electrochemical performance of activated combustion-high velocity air fuel(AC-HVAF)-sprayed Fe-Cr-Mo-W-C-B-Y amorphous coatings(ACs).Results showed that Fe-based ACs with a thickness of~300μm exhibited a fully amorphous structure with low oxidization.Originating from the reduced free volume,sub-T_(g) annealing increased the thermal stability,hardness,and surface hydrophobicity of Fe-based ACs.The enhanced corrosion resistance of sub-T_(g) annealed ACs in 3.5 wt%NaCl solution was attributed to the increased surface hydrophobicity and passivation capability.This finding elucidates the correlation between sub-T_(g) annealing and the properties of Fe-based ACs,which promotes ameliorating ACs with superior performance.
基金supported by Liaoning Joint Fund of NSFC(No.U1908219)。
文摘The effects of deep cryogenic-cycling treatment(DCT)on the mechanical properties,soft magnetic properties,and atomic scale structure of the Fe_(73.5)Si_(13.5)B_(9)Nb_(3)Cu_(1)amorphous nanocrystalline alloy were investigated.The DCT samples were obtained by subjecting the as-annealed samples to a thermal cycling process between the temperature of the supercooled liquid zone and the temperature of liquid nitrogen.Through flat plate bending testing,hardness measurements,and nanoindentation experiment,it is found that the bending toughness of the DCT samples is improved and the soft magnetic properties are also slightly enhanced.These are attributed to the rejuvenation behavior of the DCT samples,which demonstrate a higher enthalpy of relaxation.Therefore,DCT is an effective method to enhance the bending toughness of Fe-based amorphous nanocrystalline alloys without degrading the soft magnetic properties.
基金supported by the National Key R&D Program of China(No.2021YFE0100600)the National Natural Science Foundation of China(Nos.92166103,U23A20621,and 92066202)+1 种基金the Top-Notch Young Talents Program of Hubei.Yasir is grateful for financial support from the Pakistan Science Foundation(Project Reference:PSF/CRP-18th Protocol(05))the State Key Laboratory of Materials Processing and Die&Mould Technology(Project Reference:2021-008).
文摘Achieving a delicate synergy between mechanical robustness and antifouling attributes in coatings remains a formidable challenge for marine applications. Inspired by the assembly of nacre, we present a novel approach to fabricate a nacre-like metallic coating. This coating comprises an amorphous matrix with excellent anti-corrosion and anti-wear properties, as well as Cu-rich 3D interconnected channels for antifouling function. The coating is produced by high velocity oxygen fuel (HVOF) thermal spraying of surface-modified Fe-based amorphous powders with a Cu-layer. The resulting coating exhibits exceptional mechanical robustness, including high resistance to erosion, abrasion, and impact, surpassing conventional polymer antifouling coatings. Furthermore, the controlled Cu+ leaching capability of the in-situ constructed 3D interconnected diffusion channels, facilitated by the Cu-rich intersplats, contributes to the remarkable antifouling performance. This includes nearly 100 % resistance to bacterial adhesion after 1 day of immersion and over 98 % resistance to algal attachment after 7 d of immersion, resulting in a prolonged service lifetime. Notably, even after 200 cycles of wear damage, the Cu-modified amorphous coating still maintains its excellent antifouling properties. The Cu-rich intersplats play a critical role in transporting and sustainably leaching Cu ions, thereby accounting for the outstanding antifouling performance. Ultimately, we aim to advance the design of high-performance coatings suited for diverse marine applications, where both the mechanical robustness and antifouling properties are essential.
基金Project(EA201103238)supported by Nanchang Hangkong University Doctor Startup Fund,China
文摘The Fe-based amorphous metallic matrix coating （Fe-AMMC） was fabricated with the powder mixtures of Fe-based metallic glass synthesized with industrial raw materials, NiCr alloy and WC particle by high velocity oxy-fuel （HVOF） spraying. The corrosion resistance of Fe-AMMC was investigated by potentiodynamic polarization tests in 1 mol/L HCl, NaCl, H2SO4 and NaOH solutions, respectively. The surface morphologies corroded were observed by SEM. The results indicate that Fe-AMMC exhibits excellent corrosion resistance, higher corrosion resistance than 304L stainless steel in the chloride solutions. The low corrosion current density and passive current density of Fe-AMMC with a wide spontaneous passivation region are about 132.0μA/cm2 and 9.0 mA/cm2 in HCl solution, and about 2.5 μA/cm2 and 2.3 mA/cm2 in NaCl solution. The excellent corrosion resistance demonstrates that Fe-based amorphous metallic matrix powder is a viable engineering material in practical anti-corrosion and anti-wear coating applications.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 51271081 and 51301072)partially supported by the Key Fundamental Research Project from Shenzhen Research Council (No. JC201105170745A)
文摘In this study,a few Fe-based amorphous matrix composite coatings reinforced with various portions(4,8 and16 vol.%) of 31 6L stainless steel powders have been successfully produced through high velocity oxy-fuel(HVOF) spraying.The microstructure of the composite coatings was systematically characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The main structure of composite coatings remained amorphous while 31 6L stainless steel splats were distributed homogeneously in the amorphous matrix and well connected with surrounding amorphous phase.Bonding strength of coatings to the substrate was determined by 'pull-off' tensile tests.The results revealed that the31 6L stainless steel phase effectively improved the bonding strength of amorphous coatings,which is mainly contributed by the strong metallurgical bonding between stainless steel and amorphous splats.The addition of31 6L stainless steel also enhanced the ductility and fracture resistance of the coatings due to the ductile stainless steel phases,which can arrest crack propagation and increase energy dissipation.
基金supported by the National Natural Science Foundation of China(Grant Nos.51871016,51671018,11790293,51921001,51671018)111 Project(Grant No.BP0719004)+3 种基金the Program for Changjiang Scholars and Innovative Research Team in University of China(Grant No.IRT_14R05)the Projects of SKLAMM-USTB(Grant Nos.2018Z-01,2018Z-19)the financial support from the Top-Notch Young Talents Programthe financial support from the Fundamental Research Funds for the Central Universities(Grant No.FRF-TP-18-004C1)。
文摘Lead-bismuth eutectics (LBE) have considerable potential as a candidate material for accelerator-driven sub-critical systems(ADS).However,LBE corrosion and irradiation damage are two urgent challenges remaining to be solved for impellers of primary pumps.In this study,we have explored the possibility of using Fe-based amorphous coatings to overcome LBE corrosion and concurrently to sustain irradiation damage.Specifically,the Fe_(54)Cr_(18)Mo_(2)Zr_(8)B_(18)amorphous coating was prepared by high-velocity oxygen-fuel (HVOF) spraying on 316L steel and exposed to saturated oxygen static LBE for 500 h at 400℃.The coating with high thermal stability (T_(g)=615℃ and T_(x)=660℃) effectively prevented the substrate steel from being corroded by LBE owing to its unique long-range disordered atomic packing.The coating also exhibited strong irradiation resistance when being subjected to 45 dpa (displacement per atom) Au ion irradiation at room temperature,with no sign of crystallization even at the maximum implantation depth of 300 nm.Consequently,the hardness of the coatings before and after irradiation increased slightly.The current findings shed new insights into understanding corrosion mechanism and irradiation behavior of amorphous solids in LBE and expand the application range of amorphous materials.
文摘Amorphous metallic coatings with a composition of Fe48Cr15Mo14C15B6Y2 were prepared by detonation gun spraying process. Microstructural studies show that the coatings present a densely layered structure typical of thermally sprayed deposits with the porosity below 2%. Both crystallization and oxidation occurred obviously during spraying process, so that the amorphous fraction of the coatings decreased to 54% compared with fully amorphous alloy ribbons of the same component. Corrosion behavior of the amorphous coatings was investigated by electrochemical measurement. The results show that the coatings exhibit extremely wide passive region and low passive current density in 3.5% NaCl (mass fraction) and 1 mol/L HCl solutions, which illustrates excellent ability to resist localized corrosion.
基金Beijing Municipal Education Commission (00900054R5004)
文摘Amorphous metallic coatings with a composition of Fe48Cr15Mo14C15B6Y2 were prepared by means of atmospheric plasma spraying (APS) process under different conditions. The microstructure and frictional behavior were characterized simultaneously in this article. The results show that the as-deposited coatings consist of amorphous matrix and some precipitated nanocrystals, while the amorphous fraction and particle deformation as well as crystallization mechanism are significantly sensitive to the spraying parameters. The amorphous coatings express high microhardness and excellent wear resistance under dry frictional wear condition, which attributes to the inherent characteristic of amorphous phase and the dispersion strengthening of precipitated nanocrystals. The dominant wear mechanism of the amorphous coatings is fatigue wear accompanying with oxidative wear. In addition, the microhardness and wear resistance of the amorphous coatings were improved by optimizing spraying parameters, owing to the effect of both structural character and proper proportional of amorphous and nanocrystals fraction.
基金supported by the National Natural Science Foundation of China (Nos. 51471166, 51131006 and 51171119)the College Youth Scholar Fostering Program of Liaoning Province (No. LJQ2014015)
文摘In this work,the electrochemical behaviors of SAM2X5 Fe-based amorphous alloy coating and hard chromium coating were comparatively studied in 3.5 wt% NaCl solution.In comparison with the hard chromium coating,the SAM2X5 coating exhibited a wider and stable passive region with lower passive current density in the potentiodynamic polarization and showed a considerably lower current density at different anodic potentials in the potentiostatic polarization.In order to understand the passivation mechanism of the Fe-based amorphous coating,the components of the passive films formed at various polarization potentials were examined by X-ray photoelectron spectroscopy.The synergistic effect of Mo,W,Mn and Cr in the passive films was systemically analyzed.It has been revealed that Mo and W facilitate the formation of compact and stable Cr2O3 passive film at lower potentials,and the substantial enrichment of Mn in the passive film enhances the passivation ability at relatively higher potentials.The deep understanding of the passivation characteristics in multicomponent alloy systems could provide a guide for the design of corrosion-resistant amorphous alloy coatings for engineering applications.
文摘Fe-based amorphous composite coatings were fabricated on AISI 1045 steel by laser cladding. The results of the X- ray diffraction and transmission electron microscopy analyses .show the coating is composed of an amorphous phase in majority and a nanocrystaUine phuse in m,inority. Phase composition of the coating changes along the depth of the coating. The reasonable scanning speed for fabricating an amorphous composite coating is 3 500 mm/min when the laser power is 4 800 W and the laser beam diameter is 2 mm. If the scanning speed is lower than 3 500 mm/min, the intensity of the two main diffraction peaks in X-ray diffraction patterns of the coatings decreases with the scanning speeds increasing. At the same time, a broad halo peak emerges and enlarges. High laser power and fast scanning speed are the essential conditions of amorphization. The coating exhibits high microhardness.
基金financially supported by the National Natural Science Foundation of China(No.51271008)。
文摘(Zr_(0.53)Al_(0.1)Ni_(0.05)Cu_(0.3)Ti_(0.02))_(99)Y_1(at%)coating with amorphous layer of about 180μm thick was prepared on a steel substrate by using laser cladding method.The coating is compact and shows good metallurgical bonding with substrate.The microstructure,microhardness and corrosion behavior along the depth from the coating surface to the substrate were investigated.It is found that a gradient structure consisted of amorphous surface layer,amorphous-crystalline transitional layer and substrate is formed after the laser cladding.The microhardness and corrosion behavior exhibit variation with the microstructural evolution at different depths from the coating surface.The microhardness and corrosion resistance in 3.5 wt%NaCl solution of the amorphous surface layer are comparable to those of the as-cast Zr-based BMG with the same composition,and higher than those of the steel substrate.
文摘In this paper, alloy powders mixed with a molar ratio of Fe ： P ： C of 80 ： 13 ： 7 were sprayed on Q235 steel by plasma spray method to prepare coating with amorphous phases. The phase composition of the mixed alloy powders and prepared coating were characterized by X-ray diffraction （ XRD ）. The morphology and the composition cf the coating were analyzed by scanning eleetron microscopy （SEM） nnd energy dispersive apectroscopy （ EDS ）. In addition, the thermal stability ef the coating with amorphous phases was characterized by differential thermal analyzer （ DTA ）. Tile results showed that, usirtg mixed alloy powders with a molar ratio of Fe： P： C of 80：13：7, the coating containing certain amount of amorphous alloys was suceessathlly prepared through atmospheric plasma spray technique. In the coating, the main phases were determined to be Fe, FeP aad Fe2P. The crystallization of the coating started from about 461°. Tile coating was mechanically adhered to the substrate.
基金This work was supported by the National Natural Science Foundation of China(No.52161028)the Major Discipline Academic and Technical Leaders Training Program of Jiangxi Province(No.20213BCJ22017).
文摘Laser 3D printing,also known as laser additive manufacturing(LAM),is favored for its ability to form bulk metallic glass(BMG)and its composite materials(BMGcs)with freeform geometries.In this work,two different kinds of Fe_(41)Co_(7)Cr_(15)Mo_(14)C_(15)B_(6)Y_(2)amorphous coatings(A and B)were prepared by using LAM technology under air-and water-cooled conditions,respectively;meanwhile,to reduce the cracks generated due to the residual thermal stresses,coating C obtained by air-sweep annealing of B with a low energy-density laser.The morphology and amorphous content and microstructure of the coatings were investigated,the results show many cracks in coating B deposited under water-cooled conditions,and its microstructure shows an amorphous-crystal-nanocrystalline mixed structure.Cracking was suppressed in coating C,obtained by air-sweep annealing based on coating B,but the amorphous content was reduced from 32.6 to 13.4%.And the hardness and corrosion resistance of the coating will increase with the increase in the amorphous content.Finally,the internal friction behavior of a BMGcs was prepared on the basis of the process of sample C is compared with that of as-cast amorphous alloys.The results show that the low temperature internal friction behavior of BMGcs is affected by the defects produced during printing,and the high temperature internal friction behavior is affected by the precipitated hard phase.
基金The authors would like to acknowledge the financial support from China Power International Holding Ltd.(ZGDL-KJ-2022-024)Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX23_0179).
文摘A novel Fe–Cr–Mo amorphous coating,a high-temperature corrosion-resistant material for water wall protection of power plant ultra-supercritical boilers,has been prepared via arc spraying.A systematic study was conducted to evaluate the high-temperature corrosion behavior of this coating,and its resistance to corrosion at high temperatures was scientifically assessed.The results indicate that the thickness of Fe–Cr–Mo amorphous coating is approximately 350μm,exhibiting typical amorphous characteristics as confirmed by X-ray diffraction and transmission electron microscope characterization.During each stage of the 750℃corrosion test,the oxygen content of the amorphous coating was significantly lower than that of the contrast coating(PS45 alloy coating),indicating a superior corrosion protection effect at high temperature.After 100 h of continuous testing,the corrosion mass gain of the amorphous coating was only 28.62%that of PS45 coating and 3.89%that of T12 steel substrate,indicating significantly depressed high-temperature corrosion kinetics.The excellent high-temperature corrosion resistance of Fe–Cr–Mo amorphous coating is primarily attributed to the stable Fe/Cr oxide film generated by the metastable state of the amorphous state,which serves as an excellent barrier.Furthermore,under the influence of heat in a high-temperature environment,the amorphous structure gradually transforms into a nanocrystalline structure.In contrast,the oxide film of the amorphous/nanocrystalline coating has low thermal stress,leading to better adhesion with the coating and resistance to cracking and peeling,thus providing excellent sustained protection.
基金Project (51045004) supported by the National Natural Science Foundation of ChinaProject (2006AA03A219) supported by Hi-tech Research and Development Program of ChinaProject (YYYJ-0913) supported by Knowledge Innovation Project in Chinese Academy of Sciences
文摘Fe-based coating was produced on pure Ti substrate by the laser cladding technology. The composition and microstructure of the fabricated coating were analyzed by scanning electron microscopy （SEM）, X-ray diffraction （XRD） and transmission electron microscopy （TEM） technique. The tribological properties were tested through sliding against AISI52100 steel ball at different normal loads and sliding speeds. Besides, the morphologies of the worn surfaces and wear debris were analyzed by scanning electron microscopy （SEM） and three dimensional （3D） non-contact surface mapping. The results show that the prepared Fe-based coating has a high hardness of about 860 HV0.2 and exhibits an average wear rate of （0.70-2.32）×10-6 mm3/（N-m）, showing that the Fe-based coating can greatly improve the wear resistance of pure Ti substrate. The wear mechanism of the coating involves moderate adhesive and abrasive wear.
