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
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
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
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
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
To develop an ultra-high-temperature resistant coating for a reusable thermal protection system,the preparation of a tantalum-based MoSi_(2)-Mo coating by a new two-step process of multi-arc ion plating and halide act...To develop an ultra-high-temperature resistant coating for a reusable thermal protection system,the preparation of a tantalum-based MoSi_(2)-Mo coating by a new two-step process of multi-arc ion plating and halide activated pack cementation is presented.The coating has a dense structure and is well compatible with the tantalum substrate,which can be thermally shocked from room temperature to 1750℃ for 360 cycles without failure.The mechanism of the coating’s excellent resistance to high-temperature thermal shocks is that a strong-binding gradient interface and a dense SiO_(2) oxide scale with good oxygen resistance are formed by the high-temperature self-diffusion of Si.展开更多
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.
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.
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.
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This work was supported financially by the National Natural Science Foundation of China under Grant No.51901252the National Major Science and Technology Projects of China under Grant No.0101040201+1 种基金the National Defense Basic Scientific Research Program of China under Grant JCKY2017110B001the Natural Science Foundation of Hunan Province under Grant No.2020JJ5713 and No.2020JJ5737。
文摘To develop an ultra-high-temperature resistant coating for a reusable thermal protection system,the preparation of a tantalum-based MoSi_(2)-Mo coating by a new two-step process of multi-arc ion plating and halide activated pack cementation is presented.The coating has a dense structure and is well compatible with the tantalum substrate,which can be thermally shocked from room temperature to 1750℃ for 360 cycles without failure.The mechanism of the coating’s excellent resistance to high-temperature thermal shocks is that a strong-binding gradient interface and a dense SiO_(2) oxide scale with good oxygen resistance are formed by the high-temperature self-diffusion of Si.