After 32CrMoV is selected to manufacture nitrided gears coated with TiN by multi-arc ion plating, all of these uncoated gears and coated gears run in the gearbox under the same initial conditions so as to compare thei...After 32CrMoV is selected to manufacture nitrided gears coated with TiN by multi-arc ion plating, all of these uncoated gears and coated gears run in the gearbox under the same initial conditions so as to compare their difference concerning properties and microstructure. Experiment results indicate that tooth surface of the coated-TiN gears does not suffer surface abnormalities in meshed zone. Instead, the gears with nitrided case exhibit an abrasion mark on the meshed zone of tooth surface, which results in more weight loss of nitrided gears. The morphology of the surface suggests TiN film with more than 2 000 HV is so dense and smooth that coated-TiN gears have higher wear resistance compared with the uncoated gears. The microstructure of coated-TiN gears is finer, hardness is higher and its distribution of coated-TiN gears is more reliable than uncoated ones, which makes nitride layer combined with TiN film tightly. Consequently, the wear-resistance of gears has been dramatically promoted.展开更多
CrTiAIN coatings were prepared by using a home-made industrial scale multi-arc ion plating system. The coatings were found to be composites of face-center-cubic CrN and TiN. The surface roughness, microhardness, and t...CrTiAIN coatings were prepared by using a home-made industrial scale multi-arc ion plating system. The coatings were found to be composites of face-center-cubic CrN and TiN. The surface roughness, microhardness, and tribological properties of the films were significantly affected by the nitrogen pressure and dc-pulsed bias voltage applied to the substrate. The CrTiA1N coatings with the smoothest surfaces were obtained at optimum conditions of nitrogen pressure of 5.0 Pa and bias voltage of -200 V. The samples were found to exhibit a hardness of 2900 HV0.05 with an average friction coefficient of 0.16 and wear rate of 1.5× 10^-16 m^3/N.m against cemented carbide.展开更多
This paper presents the formation of Cr-O thin films on an iron substrate by multi-arc ion plating, which are intended to be used as a thermal radiation absorbent in electronic vacuum devices. Only oxygen was used as ...This paper presents the formation of Cr-O thin films on an iron substrate by multi-arc ion plating, which are intended to be used as a thermal radiation absorbent in electronic vacuum devices. Only oxygen was used as a reaction gas during deposition, the Cr-O thin film, must have high adhesion and low outgassing rate. The scratch test shows that the critical load, for an applicable Cr-O thin film deposited in oxygen atmosphere alone at a pressure of 8×10<sup>-1</sup> Pa, was as high as 6kg.展开更多
NCoCrAlSiYHf and CoNiCrAlTaY coatings which belong to protective Al 2O 3 scale forming type were deposited by multi arc ion plating technique . The effect of deposition process parameters on qualities of the coat...NCoCrAlSiYHf and CoNiCrAlTaY coatings which belong to protective Al 2O 3 scale forming type were deposited by multi arc ion plating technique . The effect of deposition process parameters on qualities of the coatings was discussed. The high temperature oxidation performances isothermal oxidation with 950℃ / 500h and 1100℃ / 100h were studied. And also, the hot corrosion performances at 700℃ and 800℃, with molten mixed salt composed of 75%wt Na 2SO 4 and 25%wt NaCl were investigated. Then the high temperature protection decaying mechanisms were proposed.展开更多
CrTiAlN/TiAlN composite coatings were deposited on cemented carbide by using a home-made industrial scale multi-arc ion plating system. The samples were studied by X-ray diffraction, scanning electron microscopy (SEM...CrTiAlN/TiAlN composite coatings were deposited on cemented carbide by using a home-made industrial scale multi-arc ion plating system. The samples were studied by X-ray diffraction, scanning electron microscopy (SEM), microhardness and ball-on-disk testing. The properties of the CrTiAlN/TiAlN coatings were significantly influenced by the microstructure and the deposition time ratio of TiAlN over CrTiAlN layers. With the increase of deposition time ratio, the microhardness of CrTiAlN/TiAlN increased from 28.6 GPa to 37.5 GPa, much higher than that of CrTiAlN coatings. The friction coefficients of the CrTiAlN/TiAlN coatings were higher than those of CrTiAlN coatings against a cemented carbide ball. The microhardness of the CrTiAlN/TiAlN coatings was changed after annealing at 800 ℃, and the friction coefficients of the annealed coatings were increased against the cemented carbide ball.展开更多
In order to investigate the microstructure of TiN and TiAlN coatings and their effect on the wear resistance of Mg alloy, TiN and TiAlN coatings were deposited on AZ91 magnesium alloy by multi-arc ion plating technolo...In order to investigate the microstructure of TiN and TiAlN coatings and their effect on the wear resistance of Mg alloy, TiN and TiAlN coatings were deposited on AZ91 magnesium alloy by multi-arc ion plating technology.TiN and Ti70Al30N coatings were prepared on the substrate,respectively,which exhibited dark golden color and compact microstructure.The microstructures of TiN and Ti70Al30N coatings were investigated by X-ray diffractometry(XRD)and scanning electron microscopy(SEM).The micro-hardness and wear resistance of TiN and Ti70Al30N coatings were investigated in comparison with the uncoated AZ91 alloy. The XRD peaks assigned to TiN and TiAlN phases are found.The hardness of TiN coatings is two times as high as that of AZ91 alloy, and Ti70Al30N coating exhibits the highest hardness.The wear resistance of the hard coatings increases obviously as result of their high hardness.展开更多
The multi-arc ion plating technology was employed to prepare the molybdenum films with thickness of 3 μm on the AISI 1045 steel. The wear and scuffing tests were carried out on the ball-on-disc tester. AFM and SEM eq...The multi-arc ion plating technology was employed to prepare the molybdenum films with thickness of 3 μm on the AISI 1045 steel. The wear and scuffing tests were carried out on the ball-on-disc tester. AFM and SEM equipped with EDS were adopted to observe and analyze the morphologies and element compositions of surface,cross-section and worn scar of the Mo film. The phase structure was studied by XRD and the bonding strength between Mo film and substrate was measured by scratching tester. The tribological experiments show that the Mo film possesses a good wear-resistance and an excellent anti-scuffing property. The failure mechanism of Mo film under extreme condition is flaking off.展开更多
CrN/(Ti,Al,Zr,Cr) N bilayer films were successfully deposited on cemented carbide( WC-8% Co) substrates by multi-arc ion plating process using two Ti-Al-Zr alloy targets and one pure Cr target. As a result of bila...CrN/(Ti,Al,Zr,Cr) N bilayer films were successfully deposited on cemented carbide( WC-8% Co) substrates by multi-arc ion plating process using two Ti-Al-Zr alloy targets and one pure Cr target. As a result of bilayered structure and addition of alloying elements( e. g. Al and Cr),the films exhibited excellent high temperature oxidation resistance under both short-term isothermal( up to 800 ℃) and long-term cyclic( up to 600 ℃) exposure conditions. Combined with pre-established outstanding tribological properties( e. g. maximum hardness of 4 000HV0. 01 and maximum adhesion strength over 200 N),these observations make such films quite a promising candidate to extend the cutting tool life span and boost the performance in high-productivity,high-speed and high-feed cutting or in dry machining conditions.展开更多
The two Ti-Al-Zr targets and one pure Cr target were used to prepare the TiAlZrCr/(Ti, Al, Zr, Cr)N gradient films on high speed steel (WlSCr4V) substrates by multi-arc ion plating technique. Short-term isothermal...The two Ti-Al-Zr targets and one pure Cr target were used to prepare the TiAlZrCr/(Ti, Al, Zr, Cr)N gradient films on high speed steel (WlSCr4V) substrates by multi-arc ion plating technique. Short-term isothermal (at 600 ℃, 700 ℃, 800℃ and 900 ℃ for 4 h) and long-terra cyclic (at 700℃ and 800℃ for 100 h) high temperature oxidation behavior of the gradient films were studied. Then the oxide scales formed on the film specimens were characterized by scanning electron microscopy (SEM), energy dispersion X-ray spectroscopy (EDS) and X-ray diffraction (XRD). It was showed that, under short-term isothermal condition, the high temperature oxidation resistance of the gradient film was excellent up to 800 ℃ and an oxide scale comprising TiO2 was observed. On the other hand, under long-term cyclic high temDerature condition, the oxidation resistance of the gradient film was excellent at about 700 ℃.展开更多
Arc ion plating (AIP) is applied to form Ti/(Ti,Cr)N/CrN multilayer coating on the surface of 316L stainless steel (SS316L) as bipolar plates for proton exchange membrane fuel cells (PEMFCs). The characterizations of ...Arc ion plating (AIP) is applied to form Ti/(Ti,Cr)N/CrN multilayer coating on the surface of 316L stainless steel (SS316L) as bipolar plates for proton exchange membrane fuel cells (PEMFCs). The characterizations of the coating are analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Interfacial contact resistance (ICR) between the coated sample and carbon paper is 4.9 m Omega cm(2) under 150 N/cm(2), which is much lower than that of the SS316L substrate. Potentiodynamic and potentiostatic tests are performed in the simulated PEMFC working conditions to investigate the corrosion behaviors of the coated sample. Superior anticorrosion performance is observed for the coated sample, whose corrosion current density is 0.12 mu A/cm(2). Surface morphology results after corrosion tests indicate that the substrate is well protected by the multilayer coating. Performances of the single cell with the multilayer coated SS316L bipolar plate are improved significantly compared with that of the cell with the uncoated SS316L bipolar plate, presenting a great potential for PEMFC application. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
The present work uses PEO solution to well disperse carbon fiber and identifies percolation thresholds of carbon fiber and carbon black which are used as conductive fillers.The resultant cathode plates have an average...The present work uses PEO solution to well disperse carbon fiber and identifies percolation thresholds of carbon fiber and carbon black which are used as conductive fillers.The resultant cathode plates have an average compressive strength of 27.3 MPa and flexural strength of 29.09 MPa,which demonstrate excellent mechanical properties.The Cu^(2+)removal efficiency was measured at different current densities in EC process with cement-based cathode plate,while the voltage changes were recorded.The results showed that the cement-based cathode plate operated stably and achieved 99.7%removal of 1 L of simulated wastewater with a Cu^(2+)concentration of 200 ppm at a current density of 8 m A/cm^(2)for 1 h.Characterization of floc and tested cathode plates,SEM and EDS analyses,and repeatability testing of the tested plates demonstrate the reusability of the plates,proving that cement-based plates can effectively replace metal cathode plates,reduce the cost of EC and improve the applicability of EC devices.展开更多
TiN coatings were deposited on polished substrates of W18Cr4V high speed steel by means of vacuum arc ion plating. The effect of cerium on adhesion between TiN coating and substrate was studied. The microstructures an...TiN coatings were deposited on polished substrates of W18Cr4V high speed steel by means of vacuum arc ion plating. The effect of cerium on adhesion between TiN coating and substrate was studied. The microstructures and composition of TiN coatings were also investigated by means of scanning electron microscope (SEM), Auger electron spectroscopy (AES), and X ray diffraction (XRD) technique. It was found that cerium is an effective modifying agent and the addition of suitable amount of cerium to TiN coatings can produce relatively excellent properties such as micro hardness, wear resistance, oxidation resistance and porosity. The experimental results show that the added cerium in TiN coatings makes a contribution to form the preferred direction along with a (111) or (222) close packed face, which may be one of the reasons that improves some properties mentioned above.展开更多
TiAlCrN coatings were deposited by means of vacuum cathodic arc ion plating technique on TC 11 (Ti-6.5Al-3.5Mo-1.5Zr-0.3Si) titanium alloy substrates. The composition, phase structure, mechanical performance, and ox...TiAlCrN coatings were deposited by means of vacuum cathodic arc ion plating technique on TC 11 (Ti-6.5Al-3.5Mo-1.5Zr-0.3Si) titanium alloy substrates. The composition, phase structure, mechanical performance, and oxidation-resistance of the nivide coatings were investi- gated by scanning electron microscopy (SEM), atomic force microscope (AFM), X-ray diffraction (XRD), auger electron spectroscopy (AES), and X-ray photoelectron microscopy (XPS). A new process for preparing protective coatings of the titanium alloy is successfully ac- quired. The experimental results indicate that the added element chromium in the TiAlN coatings make a contribution to form the (220) pre- ferred direction. The phases of the coatings are composed of (Ti,Al)N and (Ti,Cr)N. After 700~C and 800~C oxidation, AES analysis shows that the diffusion distribution of the TiAlCrN coatings emerges a step shape. From the outside to the inner, the concentrations of O, Al, and Cr reduce, but those of Ti and N increase. The Al-rich oxide is formed on the surface of the coatings, and the mixed structure of Ti-rich and Cr-rich oxides is formed in the internal layer. The oxidation resistance of the TiAlCrN coatings is excellent at the range of 700 to 800~C. Adhesion wear is the dominant mechanical characteristic for the titanium alloy at room temperature, and the protective coatings with high hardness can improve the mechanical properties of the titanium alloy. The wear resistance of the TC 11 alloy is considerably improved by the TiAlCrN coatings.展开更多
It has been reported that application of pulsed biases in arc ion plating could effectively eliminate droplet particles. The present paper aims at experimental verification of a physical model proposed previously by u...It has been reported that application of pulsed biases in arc ion plating could effectively eliminate droplet particles. The present paper aims at experimental verification of a physical model proposed previously by us which is based on particle charging and repulsion in the pulsed plasma sheath. An orthogonal experiment was designed for this purpose, using the electrical parameters of the pulsed bias for the deposition of TiN films on stainless steel substrates. The effect of these parameters on the amount and the size distribution of the particles were analyzed, and the results provided sufficient evidence for the physical model.展开更多
Owing to the characteristics of arc ion plating(AIP) technique, the structure and composition of TiAlN films can be tailored by controlling of various parameters such as compositions of target materials, N2 partial pr...Owing to the characteristics of arc ion plating(AIP) technique, the structure and composition of TiAlN films can be tailored by controlling of various parameters such as compositions of target materials, N2 partial pressure, substrate bias and so on. In this study, several titanium aluminum nitride films were deposited on 1Cr11Ni2W2MoV steel for compressor blade of areo-engine under different d.c pulse bias voltage and nitrogen partial pressure. The effects of substrate pulse bias and nitrogen partial pressure on the deposition rate, droplet formation, microstruture and elemental component of the films were investigated.展开更多
The composition demixing effect has been found often in alloy coatings deposited by cathodic arc ion plating using various alloy cathode targets. The characteristics of composition demixing phenomena were summarized. ...The composition demixing effect has been found often in alloy coatings deposited by cathodic arc ion plating using various alloy cathode targets. The characteristics of composition demixing phenomena were summarized. Beginning with the ionization zone near the surface of the cathode target, a physical model in terms of the ions generated in the ionization zone and their movement in the plating room modified by bias electric field was proposed. Based on the concept of electric charge state, the simulation calculation of the composition demixing effect was carried out. The percentage of atoms of an element in coating and from the alloy target was demonstrated by direct comparison. The influences of the composition change of the alloy target and the bias electric field on the composition demixing effect were discussed in detail. It is also proposed that the average charge states of the elements may be used to calculate the composition demixing effect and to design the composition of the alloy target.展开更多
The adhesion between the ion plated TiN coating and the base metal is improved by adding Y.The machenism of the effect of Y has been discussed as well.
In this paper, Ti-C-N nanocomposite films are deposited under different nitrogen flow rates by pulsed bias arc ion plating using Ti and graphite targets in the Ar/N2 mixture gas. The surface morphologies, compositions...In this paper, Ti-C-N nanocomposite films are deposited under different nitrogen flow rates by pulsed bias arc ion plating using Ti and graphite targets in the Ar/N2 mixture gas. The surface morphologies, compositions, microstructures, and mechanical properties of the Ti-C-N films are investigated systematically by field emission scanning electron mi- croscopy (FE-SEM), x-ray photoelectron spectroscopy (XPS), grazing incident x-ray diffraction (GIXRD), Raman spectra, and nano-indentation. The results show that the nanocrystalline Ti(C,N) phase precipitates in the film from GIXRD and XPS analysis, and Raman spectra prove the presence of diamond-like carbon, indicating the formation of nanocomposite film with microstructures comprising nanocrystalline Ti(C,N) phase embedded into a diamond-like matrix. The nitrogen flow rate has a significant effect on the composition, structure, and properties of the film. The nano-hardness and elastic modulus first increase and then decrease as nitrogen flow rate increases, reaching a maximum of 34.3 GPa and 383.2 GPa, at a nitrogen flow rate of 90 sccm, respectively.展开更多
(Ti, Al)N gradient nano-coating was deposited on the surface of 1Cr11Ni2W2MoV stainless steel by the MTP-8-800 arc ion plating equipment. And the oxidation performance at high temperature for 500h was tested under t...(Ti, Al)N gradient nano-coating was deposited on the surface of 1Cr11Ni2W2MoV stainless steel by the MTP-8-800 arc ion plating equipment. And the oxidation performance at high temperature for 500h was tested under the condition of the surrounding air temperature 700℃. The test results show that, because of the structural features of the (Ti, Al)N coating, the coating becomes the compact and continuous Al2O3 film, which can protect the basis material effectively in the process of the high temperature oxidizing. The oxidation kinetics of the coating accord with parabolic law.展开更多
TiAlSiN coating was deposited on H13 hot work mould steel using cathodic arc ion plating(CAIP). The surface-interface morphologies and phases of the obtained coating were analyzed using field emission scanning elect...TiAlSiN coating was deposited on H13 hot work mould steel using cathodic arc ion plating(CAIP). The surface-interface morphologies and phases of the obtained coating were analyzed using field emission scanning electron microscopy(FESEM) and X-ray diffraction(XRD), respectively, and the morphologies, distributions of chemical elements and profiles of worn tracks were also researched using scanning electron microscopy(SEM), energy disperse spectroscopy(EDS), and optical microscope(OM), respectively. The friction-wear performances of TiAlSiN coating under oil lubricated and dry fiction conditions were investigated, and the wear mechanisms of TiAlSiN coating were discussed. The experimental results show that the coating is primarily composed of(Ti, Al)N, AlTiN, and TiN hard phases, Si_3N_4 exists between the(Ti, Al)N crystal grains, increasing the coating microhardness to 3200 HV. The TiAlSiN coating has excellent performances of reducing friction and wear resistance, the average coefficient of friction(COF) of TiAlSiN coating under oil lubricated condition is only 0.05, lowered than the average COF of 0.211 under dry friction condition, the wear rate decreases by about 81.2% compared with that under dry friction condition. The wear mechanism of TiAlSiN coating under oil lubricated and dry friction conditions is composed of abrasive wear, fatigue wear, and abrasive wear, respectively. The internal friction of oil lubrication is a main factor of decreasing fatigue wear.展开更多
基金This project is supported by National Natural Science Foundation of China(No.50375164)Visitor Scholar Project of State Key Laboratory of Mechanical Transmission in Chongqing University,China.
文摘After 32CrMoV is selected to manufacture nitrided gears coated with TiN by multi-arc ion plating, all of these uncoated gears and coated gears run in the gearbox under the same initial conditions so as to compare their difference concerning properties and microstructure. Experiment results indicate that tooth surface of the coated-TiN gears does not suffer surface abnormalities in meshed zone. Instead, the gears with nitrided case exhibit an abrasion mark on the meshed zone of tooth surface, which results in more weight loss of nitrided gears. The morphology of the surface suggests TiN film with more than 2 000 HV is so dense and smooth that coated-TiN gears have higher wear resistance compared with the uncoated gears. The microstructure of coated-TiN gears is finer, hardness is higher and its distribution of coated-TiN gears is more reliable than uncoated ones, which makes nitride layer combined with TiN film tightly. Consequently, the wear-resistance of gears has been dramatically promoted.
基金supported by the China Ministry of Industry and Information Technology (No. 2009ZX04012-032)Basic Research Fund of Central Universities
文摘CrTiAIN coatings were prepared by using a home-made industrial scale multi-arc ion plating system. The coatings were found to be composites of face-center-cubic CrN and TiN. The surface roughness, microhardness, and tribological properties of the films were significantly affected by the nitrogen pressure and dc-pulsed bias voltage applied to the substrate. The CrTiA1N coatings with the smoothest surfaces were obtained at optimum conditions of nitrogen pressure of 5.0 Pa and bias voltage of -200 V. The samples were found to exhibit a hardness of 2900 HV0.05 with an average friction coefficient of 0.16 and wear rate of 1.5× 10^-16 m^3/N.m against cemented carbide.
文摘This paper presents the formation of Cr-O thin films on an iron substrate by multi-arc ion plating, which are intended to be used as a thermal radiation absorbent in electronic vacuum devices. Only oxygen was used as a reaction gas during deposition, the Cr-O thin film, must have high adhesion and low outgassing rate. The scratch test shows that the critical load, for an applicable Cr-O thin film deposited in oxygen atmosphere alone at a pressure of 8×10<sup>-1</sup> Pa, was as high as 6kg.
文摘NCoCrAlSiYHf and CoNiCrAlTaY coatings which belong to protective Al 2O 3 scale forming type were deposited by multi arc ion plating technique . The effect of deposition process parameters on qualities of the coatings was discussed. The high temperature oxidation performances isothermal oxidation with 950℃ / 500h and 1100℃ / 100h were studied. And also, the hot corrosion performances at 700℃ and 800℃, with molten mixed salt composed of 75%wt Na 2SO 4 and 25%wt NaCl were investigated. Then the high temperature protection decaying mechanisms were proposed.
基金supported by the International Cooperation Program of the Ministry of Science and Technology of China(No.2011DFR50580)Basic Research Funds of the Central Universities of China(No.2012202020217)
文摘CrTiAlN/TiAlN composite coatings were deposited on cemented carbide by using a home-made industrial scale multi-arc ion plating system. The samples were studied by X-ray diffraction, scanning electron microscopy (SEM), microhardness and ball-on-disk testing. The properties of the CrTiAlN/TiAlN coatings were significantly influenced by the microstructure and the deposition time ratio of TiAlN over CrTiAlN layers. With the increase of deposition time ratio, the microhardness of CrTiAlN/TiAlN increased from 28.6 GPa to 37.5 GPa, much higher than that of CrTiAlN coatings. The friction coefficients of the CrTiAlN/TiAlN coatings were higher than those of CrTiAlN coatings against a cemented carbide ball. The microhardness of the CrTiAlN/TiAlN coatings was changed after annealing at 800 ℃, and the friction coefficients of the annealed coatings were increased against the cemented carbide ball.
基金Project(1091249-1-00)supported by the Bureau of Science and Technology of Shenyang City,China
文摘In order to investigate the microstructure of TiN and TiAlN coatings and their effect on the wear resistance of Mg alloy, TiN and TiAlN coatings were deposited on AZ91 magnesium alloy by multi-arc ion plating technology.TiN and Ti70Al30N coatings were prepared on the substrate,respectively,which exhibited dark golden color and compact microstructure.The microstructures of TiN and Ti70Al30N coatings were investigated by X-ray diffractometry(XRD)and scanning electron microscopy(SEM).The micro-hardness and wear resistance of TiN and Ti70Al30N coatings were investigated in comparison with the uncoated AZ91 alloy. The XRD peaks assigned to TiN and TiAlN phases are found.The hardness of TiN coatings is two times as high as that of AZ91 alloy, and Ti70Al30N coating exhibits the highest hardness.The wear resistance of the hard coatings increases obviously as result of their high hardness.
基金Project(50235030) supported by the National Natural Science Foundation of China Project(G1999065009) supported by the National Basic Research Program of China Project(2003AA331130) supported by the Hi-tech Research and Development Program of China
文摘The multi-arc ion plating technology was employed to prepare the molybdenum films with thickness of 3 μm on the AISI 1045 steel. The wear and scuffing tests were carried out on the ball-on-disc tester. AFM and SEM equipped with EDS were adopted to observe and analyze the morphologies and element compositions of surface,cross-section and worn scar of the Mo film. The phase structure was studied by XRD and the bonding strength between Mo film and substrate was measured by scratching tester. The tribological experiments show that the Mo film possesses a good wear-resistance and an excellent anti-scuffing property. The failure mechanism of Mo film under extreme condition is flaking off.
基金financially supported by Natural Science Foundation of Liaoning Province of China(No.2014020096)Shenyang Science and Technology Plan Project of Liaoning Province of China(No.F14-231-119 )Shenyang Yongyuan Guanghui Machinery Factory Transverse Project of Liaoning Province of China(No.201521010100051)
文摘CrN/(Ti,Al,Zr,Cr) N bilayer films were successfully deposited on cemented carbide( WC-8% Co) substrates by multi-arc ion plating process using two Ti-Al-Zr alloy targets and one pure Cr target. As a result of bilayered structure and addition of alloying elements( e. g. Al and Cr),the films exhibited excellent high temperature oxidation resistance under both short-term isothermal( up to 800 ℃) and long-term cyclic( up to 600 ℃) exposure conditions. Combined with pre-established outstanding tribological properties( e. g. maximum hardness of 4 000HV0. 01 and maximum adhesion strength over 200 N),these observations make such films quite a promising candidate to extend the cutting tool life span and boost the performance in high-productivity,high-speed and high-feed cutting or in dry machining conditions.
基金supported by Program for Liaoning Excellent Talents in University (No.RC-05-05)Program for Changjiang Scholars and Innovative Research Team in University (No.IRT0713)
文摘The two Ti-Al-Zr targets and one pure Cr target were used to prepare the TiAlZrCr/(Ti, Al, Zr, Cr)N gradient films on high speed steel (WlSCr4V) substrates by multi-arc ion plating technique. Short-term isothermal (at 600 ℃, 700 ℃, 800℃ and 900 ℃ for 4 h) and long-terra cyclic (at 700℃ and 800℃ for 100 h) high temperature oxidation behavior of the gradient films were studied. Then the oxide scales formed on the film specimens were characterized by scanning electron microscopy (SEM), energy dispersion X-ray spectroscopy (EDS) and X-ray diffraction (XRD). It was showed that, under short-term isothermal condition, the high temperature oxidation resistance of the gradient film was excellent up to 800 ℃ and an oxide scale comprising TiO2 was observed. On the other hand, under long-term cyclic high temDerature condition, the oxidation resistance of the gradient film was excellent at about 700 ℃.
基金financially supported by the National Basic Research Program of China (973 Program) (no. 2012CB215500)the National Key Technology Research and Development Program of China (no. 2015BAG06B00)+1 种基金Major Program of the National Natural Science Foundation of China (no. 61433013)National Natural Science Foundation of China (no. 21206012)
文摘Arc ion plating (AIP) is applied to form Ti/(Ti,Cr)N/CrN multilayer coating on the surface of 316L stainless steel (SS316L) as bipolar plates for proton exchange membrane fuel cells (PEMFCs). The characterizations of the coating are analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Interfacial contact resistance (ICR) between the coated sample and carbon paper is 4.9 m Omega cm(2) under 150 N/cm(2), which is much lower than that of the SS316L substrate. Potentiodynamic and potentiostatic tests are performed in the simulated PEMFC working conditions to investigate the corrosion behaviors of the coated sample. Superior anticorrosion performance is observed for the coated sample, whose corrosion current density is 0.12 mu A/cm(2). Surface morphology results after corrosion tests indicate that the substrate is well protected by the multilayer coating. Performances of the single cell with the multilayer coated SS316L bipolar plate are improved significantly compared with that of the cell with the uncoated SS316L bipolar plate, presenting a great potential for PEMFC application. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
基金Funded by the National Natural Science Foundation of China (No.52078394)the Key Research and Development Program of Hubei Provincial (No.2020BAB081)。
文摘The present work uses PEO solution to well disperse carbon fiber and identifies percolation thresholds of carbon fiber and carbon black which are used as conductive fillers.The resultant cathode plates have an average compressive strength of 27.3 MPa and flexural strength of 29.09 MPa,which demonstrate excellent mechanical properties.The Cu^(2+)removal efficiency was measured at different current densities in EC process with cement-based cathode plate,while the voltage changes were recorded.The results showed that the cement-based cathode plate operated stably and achieved 99.7%removal of 1 L of simulated wastewater with a Cu^(2+)concentration of 200 ppm at a current density of 8 m A/cm^(2)for 1 h.Characterization of floc and tested cathode plates,SEM and EDS analyses,and repeatability testing of the tested plates demonstrate the reusability of the plates,proving that cement-based plates can effectively replace metal cathode plates,reduce the cost of EC and improve the applicability of EC devices.
文摘TiN coatings were deposited on polished substrates of W18Cr4V high speed steel by means of vacuum arc ion plating. The effect of cerium on adhesion between TiN coating and substrate was studied. The microstructures and composition of TiN coatings were also investigated by means of scanning electron microscope (SEM), Auger electron spectroscopy (AES), and X ray diffraction (XRD) technique. It was found that cerium is an effective modifying agent and the addition of suitable amount of cerium to TiN coatings can produce relatively excellent properties such as micro hardness, wear resistance, oxidation resistance and porosity. The experimental results show that the added cerium in TiN coatings makes a contribution to form the preferred direction along with a (111) or (222) close packed face, which may be one of the reasons that improves some properties mentioned above.
基金This study is financially supported by the National Natural Science Foundation of China(No.50271019)the Scientific Planning Project of Guangzhou City(No.2003Z2-D2071)the Natural Science Foundation of Guangdong Province,China(No.05100534).
文摘TiAlCrN coatings were deposited by means of vacuum cathodic arc ion plating technique on TC 11 (Ti-6.5Al-3.5Mo-1.5Zr-0.3Si) titanium alloy substrates. The composition, phase structure, mechanical performance, and oxidation-resistance of the nivide coatings were investi- gated by scanning electron microscopy (SEM), atomic force microscope (AFM), X-ray diffraction (XRD), auger electron spectroscopy (AES), and X-ray photoelectron microscopy (XPS). A new process for preparing protective coatings of the titanium alloy is successfully ac- quired. The experimental results indicate that the added element chromium in the TiAlN coatings make a contribution to form the (220) pre- ferred direction. The phases of the coatings are composed of (Ti,Al)N and (Ti,Cr)N. After 700~C and 800~C oxidation, AES analysis shows that the diffusion distribution of the TiAlCrN coatings emerges a step shape. From the outside to the inner, the concentrations of O, Al, and Cr reduce, but those of Ti and N increase. The Al-rich oxide is formed on the surface of the coatings, and the mixed structure of Ti-rich and Cr-rich oxides is formed in the internal layer. The oxidation resistance of the TiAlCrN coatings is excellent at the range of 700 to 800~C. Adhesion wear is the dominant mechanical characteristic for the titanium alloy at room temperature, and the protective coatings with high hardness can improve the mechanical properties of the titanium alloy. The wear resistance of the TC 11 alloy is considerably improved by the TiAlCrN coatings.
基金This work was supported by the National Natural Science Foundation of China(No.50071017)the National High-Tech Program of China(No.2002A A302507).
文摘It has been reported that application of pulsed biases in arc ion plating could effectively eliminate droplet particles. The present paper aims at experimental verification of a physical model proposed previously by us which is based on particle charging and repulsion in the pulsed plasma sheath. An orthogonal experiment was designed for this purpose, using the electrical parameters of the pulsed bias for the deposition of TiN films on stainless steel substrates. The effect of these parameters on the amount and the size distribution of the particles were analyzed, and the results provided sufficient evidence for the physical model.
文摘Owing to the characteristics of arc ion plating(AIP) technique, the structure and composition of TiAlN films can be tailored by controlling of various parameters such as compositions of target materials, N2 partial pressure, substrate bias and so on. In this study, several titanium aluminum nitride films were deposited on 1Cr11Ni2W2MoV steel for compressor blade of areo-engine under different d.c pulse bias voltage and nitrogen partial pressure. The effects of substrate pulse bias and nitrogen partial pressure on the deposition rate, droplet formation, microstruture and elemental component of the films were investigated.
文摘The composition demixing effect has been found often in alloy coatings deposited by cathodic arc ion plating using various alloy cathode targets. The characteristics of composition demixing phenomena were summarized. Beginning with the ionization zone near the surface of the cathode target, a physical model in terms of the ions generated in the ionization zone and their movement in the plating room modified by bias electric field was proposed. Based on the concept of electric charge state, the simulation calculation of the composition demixing effect was carried out. The percentage of atoms of an element in coating and from the alloy target was demonstrated by direct comparison. The influences of the composition change of the alloy target and the bias electric field on the composition demixing effect were discussed in detail. It is also proposed that the average charge states of the elements may be used to calculate the composition demixing effect and to design the composition of the alloy target.
文摘The adhesion between the ion plated TiN coating and the base metal is improved by adding Y.The machenism of the effect of Y has been discussed as well.
基金Project supported by the National Natural Science Foundation of China(Grant No.51271047)
文摘In this paper, Ti-C-N nanocomposite films are deposited under different nitrogen flow rates by pulsed bias arc ion plating using Ti and graphite targets in the Ar/N2 mixture gas. The surface morphologies, compositions, microstructures, and mechanical properties of the Ti-C-N films are investigated systematically by field emission scanning electron mi- croscopy (FE-SEM), x-ray photoelectron spectroscopy (XPS), grazing incident x-ray diffraction (GIXRD), Raman spectra, and nano-indentation. The results show that the nanocrystalline Ti(C,N) phase precipitates in the film from GIXRD and XPS analysis, and Raman spectra prove the presence of diamond-like carbon, indicating the formation of nanocomposite film with microstructures comprising nanocrystalline Ti(C,N) phase embedded into a diamond-like matrix. The nitrogen flow rate has a significant effect on the composition, structure, and properties of the film. The nano-hardness and elastic modulus first increase and then decrease as nitrogen flow rate increases, reaching a maximum of 34.3 GPa and 383.2 GPa, at a nitrogen flow rate of 90 sccm, respectively.
文摘(Ti, Al)N gradient nano-coating was deposited on the surface of 1Cr11Ni2W2MoV stainless steel by the MTP-8-800 arc ion plating equipment. And the oxidation performance at high temperature for 500h was tested under the condition of the surrounding air temperature 700℃. The test results show that, because of the structural features of the (Ti, Al)N coating, the coating becomes the compact and continuous Al2O3 film, which can protect the basis material effectively in the process of the high temperature oxidizing. The oxidation kinetics of the coating accord with parabolic law.
基金Funded by the Jiangsu Province Science and Technology Support Program(Industry)(BE2014865)
文摘TiAlSiN coating was deposited on H13 hot work mould steel using cathodic arc ion plating(CAIP). The surface-interface morphologies and phases of the obtained coating were analyzed using field emission scanning electron microscopy(FESEM) and X-ray diffraction(XRD), respectively, and the morphologies, distributions of chemical elements and profiles of worn tracks were also researched using scanning electron microscopy(SEM), energy disperse spectroscopy(EDS), and optical microscope(OM), respectively. The friction-wear performances of TiAlSiN coating under oil lubricated and dry fiction conditions were investigated, and the wear mechanisms of TiAlSiN coating were discussed. The experimental results show that the coating is primarily composed of(Ti, Al)N, AlTiN, and TiN hard phases, Si_3N_4 exists between the(Ti, Al)N crystal grains, increasing the coating microhardness to 3200 HV. The TiAlSiN coating has excellent performances of reducing friction and wear resistance, the average coefficient of friction(COF) of TiAlSiN coating under oil lubricated condition is only 0.05, lowered than the average COF of 0.211 under dry friction condition, the wear rate decreases by about 81.2% compared with that under dry friction condition. The wear mechanism of TiAlSiN coating under oil lubricated and dry friction conditions is composed of abrasive wear, fatigue wear, and abrasive wear, respectively. The internal friction of oil lubrication is a main factor of decreasing fatigue wear.