The polycrystalline Si3N4/TiN ceramic nano-multilayer films have been synthesized on Si substrates by a reactive magnetron Sputtering technique, aiming at investigating the effects of modulation ratio and modulation p...The polycrystalline Si3N4/TiN ceramic nano-multilayer films have been synthesized on Si substrates by a reactive magnetron Sputtering technique, aiming at investigating the effects of modulation ratio and modulation period on the microhardness and to elucidate the hardening mechanisms of the synthesized nanomultilayer films. The results showed that the hardness of Si3N4/TiN nano-multilayers is affected not only by modulation period, but also by modulation ratio. The hardness reaches its maximum value when modulation period equa1s a critical value λ0, which is about 12 nm with a modulation ratio of 3: 1. The maximum hardness value is about 40% higher than the value calculated from the rule of mixtures. The hardness of nano-multilayer thin films was found to decrease rapidly with increasing or decreasing modulation period from the Point of λ0. The microstructures of the nano-multilayer films have been investigated using XRD and TEM. Based on experimental results, the mechanism of the superhardness in this system was proposed.展开更多
Ti/TiN multilayer film was deposited on uranium surface by arc ion plating technique to improve fretting wear behavior. The morphology, structure and element distribution of the film were measured by scanning electric...Ti/TiN multilayer film was deposited on uranium surface by arc ion plating technique to improve fretting wear behavior. The morphology, structure and element distribution of the film were measured by scanning electric microscopy（SEM）, X-ray diffractometry（XRD） and Auger electron spectroscopy（AES）. Fretting wear tests of uranium and Ti/TiN multilayer film were carried out using pin-on-disc configuration. The fretting tests of uranium and Ti/TiN multilayer film were carried out under normal load of 20 N and various displacement amplitudes ranging from 5 to 100 μm. With the increase of the displacement amplitude, the fretting changed from partial slip regime（PSR） to slip regime（SR）. The coefficient of friction（COF） increased with the increase of displacement amplitude. The results indicated that the displacement amplitude had a strong effect on fretting wear behavior of the film. The damage of the film was very slight when the displacement amplitude was below 20 μm. The observations indicated that the delamination was the main wear mechanism of Ti/TiN multilayer film in PSR. The main wear mechanism of Ti/TiN multilayer film in SR was delamination and abrasive wear.展开更多
Ti/TiN/Zr/ZrN multilayer coatings were deposited on Cr_17Ni_2 steel substrates with different surface roughnesses by vacuum cathodic arc deposition method. Microstructure, micro-hardness, adhesion strength and cross-s...Ti/TiN/Zr/ZrN multilayer coatings were deposited on Cr_17Ni_2 steel substrates with different surface roughnesses by vacuum cathodic arc deposition method. Microstructure, micro-hardness, adhesion strength and cross-sectional morphology of the obtained multilayer coatings were investigated. The results show that the Vickers hardness of Ti/TiN/Zr/ZrN multilayer coating, with a film thickness of 11.37 μm, is 29.36 GPa. The erosion and salt spray resistance performance of Cr_17Ni_2 steel substrates can be evidently improved by Ti/TiN/Zr/ZrN multilayer coating. The surface roughness of Cr_17Ni_2 steel substrates plays an important role in determining the mechanical and erosion performances of Ti/TiN/Zr/ZrN multilayer coatings. Overall, a low value of the surface roughness of substrates corresponds to an improved performance of erosion and salt spray resistance of multilayer coatings. The optimized performance of Ti/TiN/Zr/ZrN multilayer coatings can be achieved provided that the surface roughness of Cr_17Ni_2 steel substrates is lower than 0.4μm.展开更多
TiN single coatings and TiN/Ti(C,N) multilayer coatings deposited on Cr12MoV substrate have been completed by pulsed DC plasma enhanced chemical vapor deposition(PCVD) process. The SEM, XRD and microvicker’s hardness...TiN single coatings and TiN/Ti(C,N) multilayer coatings deposited on Cr12MoV substrate have been completed by pulsed DC plasma enhanced chemical vapor deposition(PCVD) process. The SEM, XRD and microvicker’s hardness as well as the indentation test were used to study the microstructure and mechanical properties of TiN/Ti(C,N) multilayer coatings. The results show that TiN/Ti(C,N) coatings are fine and have free column structure, and carbon atoms take the place of some nitrogen atoms in Ti(C,N) coatings when lower flow ratio of CH 4 is used. The microvicker’s hardness and interfacial adhesion between TiN/Ti(C,N) coatings and Cr12MoV substrate increases more obviously than that of TiN single hard coatings due to the more dense and free column structure when process is optimized.展开更多
The TiN/Ti multilayer was deposited on Ti-811 alloy surface by magnetron sputtering(MS) technique for improving fretting fatigue(FF) resistance of the titanium alloy at elevated temperature. The element distribution, ...The TiN/Ti multilayer was deposited on Ti-811 alloy surface by magnetron sputtering(MS) technique for improving fretting fatigue(FF) resistance of the titanium alloy at elevated temperature. The element distribution, bonding strength, micro-hardness and ductility of the TiN/Ti multilayer were measured. The effects of the TiN/Ti multilayer on the tribological property and fretting fatigue resistance of the titanium alloy substrate at elevated temperature were compared. The results indicate that by MS technique a TiN/Ti multilayer with high hardness, good ductility and high bearing load capability can be prepared. The MS TiN/Ti multilayer, for its good toughness and tribological behavior, can significantly improve the wear resistance and FF resistance of the Ti-811 alloy at 350 ℃.展开更多
Magnetron sputtered (Ti, Al)N monolayer and TiN/(Ti, Al)N multilayer coatings grown on cemented carbide substrates were studied by using energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy(SEM), n...Magnetron sputtered (Ti, Al)N monolayer and TiN/(Ti, Al)N multilayer coatings grown on cemented carbide substrates were studied by using energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy(SEM), nanoindentation, Rockwell A indentation test, strength measurements and cutting tests. The results show that the (Ti, Al)N monolayer and TiN/(Ti, Al)N multilayer coatings perform good affinity to substrate, and the TiN/(Ti, Al)N multilayer coating exhibits higher hardness, higher toughness and better cutting performance compared with the (Ti, Al)N monolayer coating. Moreover, the strength measurement indicates that the physical vapour deposition (PVD) coating has no effect on the substrate strength.展开更多
The microstructure of Ti/TiN multilayer film was studied.It was shown by trans- mission electron microscopy of cross-sectional sample and respective secondary neutrals mass-spectroscopy depth profiling that the film h...The microstructure of Ti/TiN multilayer film was studied.It was shown by trans- mission electron microscopy of cross-sectional sample and respective secondary neutrals mass-spectroscopy depth profiling that the film has a periodic alternate multilayered structure:substrate /FeTi/Ti/Ti_2N/TiN/Ti_2N/Ti/Ti_2N/TiN...Ti/Ti_2N/TiN,where FeTi and Ti_2N were the transition layers formed during ion plating.Cross-sectional fracture surface of indentation samples had been obtained and studied with scanning electron microscopy.It was shown that the multilayer film deformed during indentation, formed an indentation pit and a pile-up of materials around the indentation pit.As the applied load increased deformation region extended beyond the film/substratc interface and into the substrate,the interlayer crack in the film and hole formation at the film /substrate interface were initiated.It is also shown that the multilayered Ti/TiN film offered better toughness in comparison with single layer TiN film.展开更多
The cantilever bending test,particularly monitored by an acoustic emission technique, was adopted to measure the tensile and interfacial adhesive strengths of the HCD ion plated fine TiN film on pure Ti substrate.The ...The cantilever bending test,particularly monitored by an acoustic emission technique, was adopted to measure the tensile and interfacial adhesive strengths of the HCD ion plated fine TiN film on pure Ti substrate.The behaviors of film damaging were found to be characterized by:an internal tensile stress which exceeded its tensile strength for TiN facing upward,and a shearing stress along film substrate interface which exceeded its adhesive strength for TiN facing downward.The measured tensile and adhcsive strengths are 603 and 242 MPa respectively.展开更多
文摘The polycrystalline Si3N4/TiN ceramic nano-multilayer films have been synthesized on Si substrates by a reactive magnetron Sputtering technique, aiming at investigating the effects of modulation ratio and modulation period on the microhardness and to elucidate the hardening mechanisms of the synthesized nanomultilayer films. The results showed that the hardness of Si3N4/TiN nano-multilayers is affected not only by modulation period, but also by modulation ratio. The hardness reaches its maximum value when modulation period equa1s a critical value λ0, which is about 12 nm with a modulation ratio of 3: 1. The maximum hardness value is about 40% higher than the value calculated from the rule of mixtures. The hardness of nano-multilayer thin films was found to decrease rapidly with increasing or decreasing modulation period from the Point of λ0. The microstructures of the nano-multilayer films have been investigated using XRD and TEM. Based on experimental results, the mechanism of the superhardness in this system was proposed.
基金Projects(U1530136,51375407) supported by the National Natural Science Foundation of ChinaProject(2017TD0017) supported by the Young Scientific Innovation Team of Science and Technology of Sichuan Province,China
文摘Ti/TiN multilayer film was deposited on uranium surface by arc ion plating technique to improve fretting wear behavior. The morphology, structure and element distribution of the film were measured by scanning electric microscopy（SEM）, X-ray diffractometry（XRD） and Auger electron spectroscopy（AES）. Fretting wear tests of uranium and Ti/TiN multilayer film were carried out using pin-on-disc configuration. The fretting tests of uranium and Ti/TiN multilayer film were carried out under normal load of 20 N and various displacement amplitudes ranging from 5 to 100 μm. With the increase of the displacement amplitude, the fretting changed from partial slip regime（PSR） to slip regime（SR）. The coefficient of friction（COF） increased with the increase of displacement amplitude. The results indicated that the displacement amplitude had a strong effect on fretting wear behavior of the film. The damage of the film was very slight when the displacement amplitude was below 20 μm. The observations indicated that the delamination was the main wear mechanism of Ti/TiN multilayer film in PSR. The main wear mechanism of Ti/TiN multilayer film in SR was delamination and abrasive wear.
基金Project(2011B050400007)supported by the International Cooperation Program of Guangdong Province,China
文摘Ti/TiN/Zr/ZrN multilayer coatings were deposited on Cr_17Ni_2 steel substrates with different surface roughnesses by vacuum cathodic arc deposition method. Microstructure, micro-hardness, adhesion strength and cross-sectional morphology of the obtained multilayer coatings were investigated. The results show that the Vickers hardness of Ti/TiN/Zr/ZrN multilayer coating, with a film thickness of 11.37 μm, is 29.36 GPa. The erosion and salt spray resistance performance of Cr_17Ni_2 steel substrates can be evidently improved by Ti/TiN/Zr/ZrN multilayer coating. The surface roughness of Cr_17Ni_2 steel substrates plays an important role in determining the mechanical and erosion performances of Ti/TiN/Zr/ZrN multilayer coatings. Overall, a low value of the surface roughness of substrates corresponds to an improved performance of erosion and salt spray resistance of multilayer coatings. The optimized performance of Ti/TiN/Zr/ZrN multilayer coatings can be achieved provided that the surface roughness of Cr_17Ni_2 steel substrates is lower than 0.4μm.
文摘TiN single coatings and TiN/Ti(C,N) multilayer coatings deposited on Cr12MoV substrate have been completed by pulsed DC plasma enhanced chemical vapor deposition(PCVD) process. The SEM, XRD and microvicker’s hardness as well as the indentation test were used to study the microstructure and mechanical properties of TiN/Ti(C,N) multilayer coatings. The results show that TiN/Ti(C,N) coatings are fine and have free column structure, and carbon atoms take the place of some nitrogen atoms in Ti(C,N) coatings when lower flow ratio of CH 4 is used. The microvicker’s hardness and interfacial adhesion between TiN/Ti(C,N) coatings and Cr12MoV substrate increases more obviously than that of TiN single hard coatings due to the more dense and free column structure when process is optimized.
基金Projects(50671085, 50371060) supported by the National Natural Science Foundation of ChinaProject(2007AA03Z521) supported by the National High-tech Research and Development Program of China
文摘The TiN/Ti multilayer was deposited on Ti-811 alloy surface by magnetron sputtering(MS) technique for improving fretting fatigue(FF) resistance of the titanium alloy at elevated temperature. The element distribution, bonding strength, micro-hardness and ductility of the TiN/Ti multilayer were measured. The effects of the TiN/Ti multilayer on the tribological property and fretting fatigue resistance of the titanium alloy substrate at elevated temperature were compared. The results indicate that by MS technique a TiN/Ti multilayer with high hardness, good ductility and high bearing load capability can be prepared. The MS TiN/Ti multilayer, for its good toughness and tribological behavior, can significantly improve the wear resistance and FF resistance of the Ti-811 alloy at 350 ℃.
文摘Magnetron sputtered (Ti, Al)N monolayer and TiN/(Ti, Al)N multilayer coatings grown on cemented carbide substrates were studied by using energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy(SEM), nanoindentation, Rockwell A indentation test, strength measurements and cutting tests. The results show that the (Ti, Al)N monolayer and TiN/(Ti, Al)N multilayer coatings perform good affinity to substrate, and the TiN/(Ti, Al)N multilayer coating exhibits higher hardness, higher toughness and better cutting performance compared with the (Ti, Al)N monolayer coating. Moreover, the strength measurement indicates that the physical vapour deposition (PVD) coating has no effect on the substrate strength.
文摘The microstructure of Ti/TiN multilayer film was studied.It was shown by trans- mission electron microscopy of cross-sectional sample and respective secondary neutrals mass-spectroscopy depth profiling that the film has a periodic alternate multilayered structure:substrate /FeTi/Ti/Ti_2N/TiN/Ti_2N/Ti/Ti_2N/TiN...Ti/Ti_2N/TiN,where FeTi and Ti_2N were the transition layers formed during ion plating.Cross-sectional fracture surface of indentation samples had been obtained and studied with scanning electron microscopy.It was shown that the multilayer film deformed during indentation, formed an indentation pit and a pile-up of materials around the indentation pit.As the applied load increased deformation region extended beyond the film/substratc interface and into the substrate,the interlayer crack in the film and hole formation at the film /substrate interface were initiated.It is also shown that the multilayered Ti/TiN film offered better toughness in comparison with single layer TiN film.
文摘The cantilever bending test,particularly monitored by an acoustic emission technique, was adopted to measure the tensile and interfacial adhesive strengths of the HCD ion plated fine TiN film on pure Ti substrate.The behaviors of film damaging were found to be characterized by:an internal tensile stress which exceeded its tensile strength for TiN facing upward,and a shearing stress along film substrate interface which exceeded its adhesive strength for TiN facing downward.The measured tensile and adhcsive strengths are 603 and 242 MPa respectively.
