TaN/NbN multilayered coatings with nanoscale bilayer periods were synthesized at different Ar/N2 flow rates by RF （radio frequency） magnetron sputtering. XRD （X-ray diffraction） and Nano Indenter System were emplo...TaN/NbN multilayered coatings with nanoscale bilayer periods were synthesized at different Ar/N2 flow rates by RF （radio frequency） magnetron sputtering. XRD （X-ray diffraction） and Nano Indenter System were employed to investigate the influence of Ar/N2 flow rate （FAr：FN2） on microstructure and mechanical properties of the coatings. The low-angle XRD pattern indicated a well-defined composition modulation and layer structure of the multilayered coating. All multilayered coatings almost revealed higher hardness than the rule-of-mixtures value of monolithic TaN and NbN coatings. At FAr：FN2=10, the multilayered coating possessed desirable hardness, elastic modulus, internal stress, and fracture resistance, compared with ones synthesized at other Ar/N2 flow rates. The layered structure with strong mixture of TaN （110）, （111）, （200） and Nb2N （101）textures should be related to the enhanced mechanical properties.展开更多
TiN/CrN multilayered hard coatings with TiCrN interlayer were deposited onhigh speed steel substrates by using a filtered cathodic vacuum arc technique. The structure andcomposition of the coatings were characterized ...TiN/CrN multilayered hard coatings with TiCrN interlayer were deposited onhigh speed steel substrates by using a filtered cathodic vacuum arc technique. The structure andcomposition of the coatings were characterized by scanning electron microscopy (SEM) and Augerelectron spectroscopy (AES). A high adhesion of up to 80 N was demonstrated by scratching tests forthe multi-layered coatings. Nanoindentation tests were performed to determine the hardness andelastic modulus of the coatings as a function of the multiplayer modulation period. It was observedthat the hardness of the multilayered coatings is higher than those of either TiN or CrN singlecoatings, and it increases with decreasing modulation periods, which is consistent with predictionsfrom the Hall-Petch type strengthening mechanism, though at small modulation periods, deviation fromthe Hall-Petch relation has been observed for the multilayered coatings. The life-span of drillscoated with TiN/CrN multilayered is triple as long as that coated with TiN layer.展开更多
Fracture behavior of CrN coatings deposited on the surface of silicon and AISI52100 steel by different energy ion beam assisted magnetron sputtering technique （IBAMS） was studied using indentation and dynamic cycle ...Fracture behavior of CrN coatings deposited on the surface of silicon and AISI52100 steel by different energy ion beam assisted magnetron sputtering technique （IBAMS） was studied using indentation and dynamic cycle impact. It is found that, for the coatings on silicon substrate, the cracks form in the indentation corners and then propagate outward under Vickers indentation. The coating prepared using ion assisted energy of 800 eV shows the highest fracture resistance due to its compact structure. Under Rockwell indentation, only finer radial cracks are found in the CrN coating on AISI 52100 steel without ion assisting while in the condition of ion assisting energy of 800 eV, radial, lateral cracks and spalling appear in the vicinity of indentation. The fracture of CrN coatings under dynamic cycle impact is similar to fatigue. The impact fracture resistance of CrN coatings increases with the increase of ion assisting energy.展开更多
The coating substrate bonding strengths under different intermixing processes were evaluated by scratch and spherical rolling contact fatigue methods. The results show that for low bombarding energy of N ions dynamic ...The coating substrate bonding strengths under different intermixing processes were evaluated by scratch and spherical rolling contact fatigue methods. The results show that for low bombarding energy of N ions dynamic recoiling at 10 keV and 20 keV, the coating layers are of excellent bonding strengths. The bonding strength of CrN coating with 40 keV static recoiling is higher than that of low energy(20 keV). On the other hand, the bonding strength of coating with 40 keV dynamic recoiling is much lower than that of static recoiling at the same energy and even less than that of dynamic recoiling intermixings at 10 keV and 20 keV energy. The results of scratch and spherical rolling contact fatigue methods exhibit the same trend for each group of recoiling methods, yet the results of the scratch and fatigue tests for two groups do not agree with each other.展开更多
The multilayer gradient CrN/ZrN coatings were synthesized by a dual cathode DC magnetron sputtering.The influence of different species of reaction gases and partial pressures on structure and mechanical properties was...The multilayer gradient CrN/ZrN coatings were synthesized by a dual cathode DC magnetron sputtering.The influence of different species of reaction gases and partial pressures on structure and mechanical properties was investigated using XRD, AES, XPS, and nanoindentation. The results show that N2-NH3 mixture process gas is of benefit to the synthesis of superhard multilayered gradient CrN/ZrN coatings. The presence of the preferred orientations of CrN(111), (200) and ZrN (111), (220) in the structure is a main reason for superhardness of multilayered gradient coatings.展开更多
Based on the cermet double layer structure, Nb-NbN multi-layer films for solar selective coatings were deposited by direct current reactive magnetron sputtering. The Nb/Nb-NbN/Al2O3 trilayered structure was deposited ...Based on the cermet double layer structure, Nb-NbN multi-layer films for solar selective coatings were deposited by direct current reactive magnetron sputtering. The Nb/Nb-NbN/Al2O3 trilayered structure was deposited on a stainless steel (SS) substrate by using a single niobium target. The expected components were adjusted by changing the gas flowing ratios of Ar: N2. The Al2O3 antireflective layer on the top of the film was produced by r. f. magnetron sputtering using Al2O3 ceramic target. A solar absorptivity of 0.94 and a normal emissivity of 0.16 at room temperature have been achieved for the coating. Thermal vacuum aging to the samples was carried out at 350 and 500 ℃ for 1 h. The results show a good thermal stability. Microstructure and its dependence on temperature of the Nb, NbN and Nb-NbN single layers were investigated, respectively.展开更多
Three CrN coatings were deposited on the Inconel X750 through the metal vapor vacuum arc ion implantation and the magnetic filtered cathodic vacuum arc deposition system(MEVVA-FCVA) with the N2 flow rates of 10,50,and...Three CrN coatings were deposited on the Inconel X750 through the metal vapor vacuum arc ion implantation and the magnetic filtered cathodic vacuum arc deposition system(MEVVA-FCVA) with the N2 flow rates of 10,50,and 100sccm, respectively.The surface morphologies and cross-section morphologies of the CrN coatings were obtained through scanning electron microscopy(SEM) and an optical profilometer.The microstructures of the coatings were characterized through X-ray diffraction(XRD).The hardness and the elastic modulus of the coatings were tested by a nano-hardness tester.The adhesion strength and friction coefficients were investigated through scratch tests and ball-on-disk tests and the wear tracks were tested by the optical profilometer. The experimental results indicate that the CrN coating deposited on the Inconel X750 substrate displays a uniform thickness and a smooth surface. The mechanical properties behaves well as the N2 flow rate varies.The CrN coating significantly reduces the friction coefficient fluctuation and improves the antiadhesion and anti-wear properties of the Inconel X750.展开更多
DIN 1.2343 and 1.2367 steels are commonly used as die materials in aluminum extrusion, and single/duplex/multi-coatings enhance their surface properties. The design of an appropriate substrate/coating system is import...DIN 1.2343 and 1.2367 steels are commonly used as die materials in aluminum extrusion, and single/duplex/multi-coatings enhance their surface properties. The design of an appropriate substrate/coating system is important for improving the tribological performance of these steels under service conditions because the load-carrying capacity of the system can be increased by decreasing the plastic deformation of the substrate. In this study, the tribological behavior of CrN-coated Cr–Mo–V steels(DIN 1.2343, 1.2367, and 1.2999 grades) was investigated using different setups and tribological pairs at room and elevated temperatures. The aim of this study was to reveal the wear resistance of a suggested system(1.2999/CrN) not yet studied and to understand both the wear and the failure characteristics of coated systems. The results showed that(i) among the steels studied, the DIN 1.2999 grade steel exhibited the lowest friction coefficient because it had the highest load-carrying capacity as a result of secondary hardening at elevated temperatures;(ii) at room temperature, both abrasive tracks and adhesive layers were observed on the worn surfaces; and(iii) a combination of chemical reactions and progressive oxidation caused aluminum adhesion on the worn surface, and the detachment of droplets and microcracking were the characteristic damage mechanisms at high temperatures.展开更多
Closed Field Unbalanced Magnetron Sputter Ion Plating (CFUBMSIP) systems have been used increasingly for PVD coating in recent years. TiN and CrN coatings, commonly used as the basic coating for a number of different ...Closed Field Unbalanced Magnetron Sputter Ion Plating (CFUBMSIP) systems have been used increasingly for PVD coating in recent years. TiN and CrN coatings, commonly used as the basic coating for a number of different hard coatings, have been chosen to study the coating process parameters for the CFUBMSIP system. In this paper, the process parameters, such as substrate temperature, substrate bias and OEM control, have been carefully examined to achieve hard and wear-resistance coatings with good adhesion. The coating structure and orientation were found to change according to the coating parameters. The Rockwell test and Scratch test were carried out to examine the coating adhesion; pin-on-disc testing was used to estimate the wear-resistant; micro-hardness was also used to determine coating hardness. HSS drill testing has been carried out to study the general properties of the coating for cutting tool application. A combination of process parameters can be selected to achieve good performance for the TiN and CrN coatings.展开更多
文摘TaN/NbN multilayered coatings with nanoscale bilayer periods were synthesized at different Ar/N2 flow rates by RF （radio frequency） magnetron sputtering. XRD （X-ray diffraction） and Nano Indenter System were employed to investigate the influence of Ar/N2 flow rate （FAr：FN2） on microstructure and mechanical properties of the coatings. The low-angle XRD pattern indicated a well-defined composition modulation and layer structure of the multilayered coating. All multilayered coatings almost revealed higher hardness than the rule-of-mixtures value of monolithic TaN and NbN coatings. At FAr：FN2=10, the multilayered coating possessed desirable hardness, elastic modulus, internal stress, and fracture resistance, compared with ones synthesized at other Ar/N2 flow rates. The layered structure with strong mixture of TaN （110）, （111）, （200） and Nb2N （101）textures should be related to the enhanced mechanical properties.
基金This work was financially supported by the Science Foundation of Lanzhou Institute Chemistry and Physics, Chinese Academy of Science (No.01-03).
文摘TiN/CrN multilayered hard coatings with TiCrN interlayer were deposited onhigh speed steel substrates by using a filtered cathodic vacuum arc technique. The structure andcomposition of the coatings were characterized by scanning electron microscopy (SEM) and Augerelectron spectroscopy (AES). A high adhesion of up to 80 N was demonstrated by scratching tests forthe multi-layered coatings. Nanoindentation tests were performed to determine the hardness andelastic modulus of the coatings as a function of the multiplayer modulation period. It was observedthat the hardness of the multilayered coatings is higher than those of either TiN or CrN singlecoatings, and it increases with decreasing modulation periods, which is consistent with predictionsfrom the Hall-Petch type strengthening mechanism, though at small modulation periods, deviation fromthe Hall-Petch relation has been observed for the multilayered coatings. The life-span of drillscoated with TiN/CrN multilayered is triple as long as that coated with TiN layer.
基金Funded by the National Natural Science Foundation of China(No. 50771070)Shanxi Province Science and Technology Key Projects (No. 20100321078-02)
文摘Fracture behavior of CrN coatings deposited on the surface of silicon and AISI52100 steel by different energy ion beam assisted magnetron sputtering technique （IBAMS） was studied using indentation and dynamic cycle impact. It is found that, for the coatings on silicon substrate, the cracks form in the indentation corners and then propagate outward under Vickers indentation. The coating prepared using ion assisted energy of 800 eV shows the highest fracture resistance due to its compact structure. Under Rockwell indentation, only finer radial cracks are found in the CrN coating on AISI 52100 steel without ion assisting while in the condition of ion assisting energy of 800 eV, radial, lateral cracks and spalling appear in the vicinity of indentation. The fracture of CrN coatings under dynamic cycle impact is similar to fatigue. The impact fracture resistance of CrN coatings increases with the increase of ion assisting energy.
文摘The coating substrate bonding strengths under different intermixing processes were evaluated by scratch and spherical rolling contact fatigue methods. The results show that for low bombarding energy of N ions dynamic recoiling at 10 keV and 20 keV, the coating layers are of excellent bonding strengths. The bonding strength of CrN coating with 40 keV static recoiling is higher than that of low energy(20 keV). On the other hand, the bonding strength of coating with 40 keV dynamic recoiling is much lower than that of static recoiling at the same energy and even less than that of dynamic recoiling intermixings at 10 keV and 20 keV energy. The results of scratch and spherical rolling contact fatigue methods exhibit the same trend for each group of recoiling methods, yet the results of the scratch and fatigue tests for two groups do not agree with each other.
基金Project(043801011) supported by Applied Basic Key Project of Tianjin Project(50472026) supported by the National Natural Science Foundation of China Project(GJDF01) also supported partly by Joint Project of Tianjin Municipal University and Nankai University and Tianjin University, State Education Ministry
文摘The multilayer gradient CrN/ZrN coatings were synthesized by a dual cathode DC magnetron sputtering.The influence of different species of reaction gases and partial pressures on structure and mechanical properties was investigated using XRD, AES, XPS, and nanoindentation. The results show that N2-NH3 mixture process gas is of benefit to the synthesis of superhard multilayered gradient CrN/ZrN coatings. The presence of the preferred orientations of CrN(111), (200) and ZrN (111), (220) in the structure is a main reason for superhardness of multilayered gradient coatings.
基金This work was financially supported by the National Natural Science Foundation of China (NSFC) (No.50471004), Program for New Century Excellent Talents in University (NCET) and Foundation from Engineering Research Institute, Peking University(ERIPKU)(No.204031).
文摘Based on the cermet double layer structure, Nb-NbN multi-layer films for solar selective coatings were deposited by direct current reactive magnetron sputtering. The Nb/Nb-NbN/Al2O3 trilayered structure was deposited on a stainless steel (SS) substrate by using a single niobium target. The expected components were adjusted by changing the gas flowing ratios of Ar: N2. The Al2O3 antireflective layer on the top of the film was produced by r. f. magnetron sputtering using Al2O3 ceramic target. A solar absorptivity of 0.94 and a normal emissivity of 0.16 at room temperature have been achieved for the coating. Thermal vacuum aging to the samples was carried out at 350 and 500 ℃ for 1 h. The results show a good thermal stability. Microstructure and its dependence on temperature of the Nb, NbN and Nb-NbN single layers were investigated, respectively.
基金Funded by the Special Plan of Scientific and Technological Innovation for Graduate Student in Beijing Institute of Technology(2015CX10015)the National Natural Science Foundation of China(51405455)
文摘Three CrN coatings were deposited on the Inconel X750 through the metal vapor vacuum arc ion implantation and the magnetic filtered cathodic vacuum arc deposition system(MEVVA-FCVA) with the N2 flow rates of 10,50,and 100sccm, respectively.The surface morphologies and cross-section morphologies of the CrN coatings were obtained through scanning electron microscopy(SEM) and an optical profilometer.The microstructures of the coatings were characterized through X-ray diffraction(XRD).The hardness and the elastic modulus of the coatings were tested by a nano-hardness tester.The adhesion strength and friction coefficients were investigated through scratch tests and ball-on-disk tests and the wear tracks were tested by the optical profilometer. The experimental results indicate that the CrN coating deposited on the Inconel X750 substrate displays a uniform thickness and a smooth surface. The mechanical properties behaves well as the N2 flow rate varies.The CrN coating significantly reduces the friction coefficient fluctuation and improves the antiadhesion and anti-wear properties of the Inconel X750.
文摘DIN 1.2343 and 1.2367 steels are commonly used as die materials in aluminum extrusion, and single/duplex/multi-coatings enhance their surface properties. The design of an appropriate substrate/coating system is important for improving the tribological performance of these steels under service conditions because the load-carrying capacity of the system can be increased by decreasing the plastic deformation of the substrate. In this study, the tribological behavior of CrN-coated Cr–Mo–V steels(DIN 1.2343, 1.2367, and 1.2999 grades) was investigated using different setups and tribological pairs at room and elevated temperatures. The aim of this study was to reveal the wear resistance of a suggested system(1.2999/CrN) not yet studied and to understand both the wear and the failure characteristics of coated systems. The results showed that(i) among the steels studied, the DIN 1.2999 grade steel exhibited the lowest friction coefficient because it had the highest load-carrying capacity as a result of secondary hardening at elevated temperatures;(ii) at room temperature, both abrasive tracks and adhesive layers were observed on the worn surfaces; and(iii) a combination of chemical reactions and progressive oxidation caused aluminum adhesion on the worn surface, and the detachment of droplets and microcracking were the characteristic damage mechanisms at high temperatures.
文摘Closed Field Unbalanced Magnetron Sputter Ion Plating (CFUBMSIP) systems have been used increasingly for PVD coating in recent years. TiN and CrN coatings, commonly used as the basic coating for a number of different hard coatings, have been chosen to study the coating process parameters for the CFUBMSIP system. In this paper, the process parameters, such as substrate temperature, substrate bias and OEM control, have been carefully examined to achieve hard and wear-resistance coatings with good adhesion. The coating structure and orientation were found to change according to the coating parameters. The Rockwell test and Scratch test were carried out to examine the coating adhesion; pin-on-disc testing was used to estimate the wear-resistant; micro-hardness was also used to determine coating hardness. HSS drill testing has been carried out to study the general properties of the coating for cutting tool application. A combination of process parameters can be selected to achieve good performance for the TiN and CrN coatings.
