A series of single bcc,bcc plus fcc duplex and single fcc microcrystalline coatings of 1Cr18Ni9Ti stainless steel were prepared by using sputtering technique.The resistance against pitting corrosion was studied by mea...A series of single bcc,bcc plus fcc duplex and single fcc microcrystalline coatings of 1Cr18Ni9Ti stainless steel were prepared by using sputtering technique.The resistance against pitting corrosion was studied by measurements of pitting corrosion potentials and electrochemical noise during initiation of corrosion pits.The results show that the sputtered coatings with single bcc phase or single fcc structure are more resistant to pitting corrosion than those with bcc plus fcc duplex phase structure.展开更多
Ti(C, N)-TiB2 composite coatings were deposited by means of reactive low pressure plasma spraying (LPPS) based on the technology of self-propagating high-temperature synthesis (SHS). The original powders were mixtures...Ti(C, N)-TiB2 composite coatings were deposited by means of reactive low pressure plasma spraying (LPPS) based on the technology of self-propagating high-temperature synthesis (SHS). The original powders were mixtures of Ti and B4C powders. The powders were mixed by ball mill and then spray-dried and at last sintered to be suitable for spraying. Two spraying distances were selected for LPPS. Scanning electron microscopy (SEM) was used to investigate the morphologies of powders for spraying and the microstructures of the coatings. The phase compositions of coatings were measured by X-ray diffraction (XRD). Spray-dried and sintered powders are denser and better bond than only spray-dried powders. The composite coating is composed of TiB2, TiC0.3N0.7, TiN0.3, Ti4N3-x and impurity phase of Ti5Si3 with 300 mm spraying distance. Partly unreacted B4C powders remained in the coating for 240 mm spraying distance, which may be inadequate reaction. No titanium oxide was detected in the composite coating for the relative high vacuum degree of LPPS. The anti-corrosion property of LPPS sprayed Ti(C, N)-TiB2 composite coating with 300 mm spraying distance in electrolytic solution is superior to that of 240 mm spraying distance. Microhardness of Ti(C, N)-TiB2 composite coating is relatively low due to the unconsolidated structure of the coating. The solving methods to improve property of composite coating are finally put forward in the paper.展开更多
SiCf/Ti-6Al-4V composites were fabricated by the powder-coated fiber method. The precursor fiber was prepared under the optimized parameter, and the composites were made using the vacuum hot pressure method. The influ...SiCf/Ti-6Al-4V composites were fabricated by the powder-coated fiber method. The precursor fiber was prepared under the optimized parameter, and the composites were made using the vacuum hot pressure method. The influence of heat exposure time on products of thelinterfacial reaction was investigated using scanning electron microscope （SEM） and analytical transmission electron microscope （TEM） with energy dispersive spectrometer （EDS）. The main products are TiC and Ti5Si3 after vacuum exposing the samples at 700℃ for 50 h. The growth dynamics of interracial reaction products was analyzed quantitatively, which fitted the parabola rule. The activity energy of the reaction was 252 kJ·mol^-1.展开更多
The coating of Ni W P was deposited as base layer, and then the composite coating of Ni Ti(particles) Re(rare earth) was deposited subsequently on the surface of diamond using electroless plating by adding 2...The coating of Ni W P was deposited as base layer, and then the composite coating of Ni Ti(particles) Re(rare earth) was deposited subsequently on the surface of diamond using electroless plating by adding 2～3 μm Ti particles and trace rare earth salt to bath solution. Ti particles deposited on the surface of diamond were found by SEM and formation of TiC was verified by X ray diffraction analysis after heat treatment of the coatings in vacuum at 900 ℃. The binding strength between the coated diamond and the metal matrix was improved effectively in the diamond composite based on metal cement.展开更多
Ti-Ni-Mo-Si composite coating was fabricated on mild steel by reactive braze coating process with Ti61. 9Ni24. 6Si4. 411409.1 （ wt. % ） powders as the raw materials. Microstr^cture of the coating was characterized b...Ti-Ni-Mo-Si composite coating was fabricated on mild steel by reactive braze coating process with Ti61. 9Ni24. 6Si4. 411409.1 （ wt. % ） powders as the raw materials. Microstr^cture of the coating was characterized by optical microscopy, scanning electron microscopy, X-ray diffraction and energy dispersive spectroscopy and micro-hardness tester. Results indicate that the Ti-Ni-Mo-Si composite coating is metallurgically bonded to the mild steel substrate and has high hardness. The microstructure of the coating consists of the reinforcement of Ti5 Si3 and Mo9 Ti4 particles and the matrix of eutectic NiTi2. Due to the poor wettability of NiTi2 liquid at low temperature, TisSi3 and Mo9 Ti4 do not uniformly distribute in the NiTi2 matrix.展开更多
Metallization of the ceramic surfaces of Si3N4 and Al2O3 was carried out in a composite diffusion coating vacuum furnace using a Ti-Cu composite target. The experimental process and influencing factors were discussed....Metallization of the ceramic surfaces of Si3N4 and Al2O3 was carried out in a composite diffusion coating vacuum furnace using a Ti-Cu composite target. The experimental process and influencing factors were discussed. Optical microscope （OM） , energy dispersive spectroscopy （EDS） , scanning electron microscopy （SEM） , X-ray diffusion （XRD） and sound emissive scratch test （SEST） were applied to evaluate the alloy layer formed on the ceramic surface. It was indicated that the diffusion coating alloy layer contained Cu, Ti, Fe, Al and Si etc. XRD result indicated that the diffusion coating alloy layer was composed of CuTi2, Cu, Si2 Ti and CuTi, Al2 TiO5 , Ti3O5. It was found that the diffusion coating alloy layer got bonded with ceramic well, and no spaUation occurred under the maximum load of 100 N. Deposited Si3N4 ceramic was welded with Q235 and the joining quality was examined. Robust joint was formed between Si3N4 ceramic/Q235. This present method has advantages in high efficiency and low cost and provides a new approach for producing ceramic and metal bond.展开更多
In this work, TiO2/Ti composite films were fabricated by 2-setp MCT and the following high temperature oxidation. Antibacterial activity of the composite films treated by ultrasonic cleaning to increase the performanc...In this work, TiO2/Ti composite films were fabricated by 2-setp MCT and the following high temperature oxidation. Antibacterial activity of the composite films treated by ultrasonic cleaning to increase the performance reliability was examined. The prepared TiO2/Ti composite films showed high photocatalytic activity in the degradation of methylene blue solution. It is obvious that? TiO2/Ti composite films have antibacterial activity under UV irradiation.展开更多
It is showed that there are Ti 3Al, Ti 2Cu and β phase in the interface of Ti/Ti Al composites reinforced with Y 2O 3 Cr composite soft coated Ti fiber, and that interface bonding is intact. Bending strength ...It is showed that there are Ti 3Al, Ti 2Cu and β phase in the interface of Ti/Ti Al composites reinforced with Y 2O 3 Cr composite soft coated Ti fiber, and that interface bonding is intact. Bending strength of the composites can be increased by 26%, to 709 MPa, and bending deflection increased slightly compared with the Ti/Ti Al composites reinforced by Ti fibers coated with Y 2O 3.展开更多
A continuous loading push-out test technique was used to measure the interfacial shear strength of SiC fiber reinforced Ti matrix composites. The interfacial shear strength of samples as-fabricated and after heat expo...A continuous loading push-out test technique was used to measure the interfacial shear strength of SiC fiber reinforced Ti matrix composites. The interfacial shear strength of samples as-fabricated and after heat exposed at 700 and 800℃ for 50 h was successfully determined. It has been found that the interfacial shear strength of the specimen exposed at 700℃ was higher than that of as-prepared and exposed samples at 800℃. The shear strength of the as-prepared samples was about 112.45 MPa, and increased to about 153.77 MPa after heat-treating at 700℃ for 50 h, but decreased to 133.11 MPa after treating at 800℃ for 50 h. Scanning electron microscope （SEM） was used to investigate the interfacial morphology of the samples. The brittle phase was the main products of interface for samples exposed at 800℃, and the interface was easily peeled off.展开更多
In order to evaluate the interfacial reaction, a SiCf/Ti (TA1) composite was fabricated by a vacuum hot pressing method and then heat-treated in vacuum at 800℃ for up to 100 h. The elemental distributions of C, Si an...In order to evaluate the interfacial reaction, a SiCf/Ti (TA1) composite was fabricated by a vacuum hot pressing method and then heat-treated in vacuum at 800℃ for up to 100 h. The elemental distributions of C, Si and Ti at the interfacial reaction zone were investigated. It was found that the reaction zone occurs during the fabrication process and continuously grows at high temperature because the Si and C atoms diffuse from SiC fibers to the matrix and Ti atoms diffuse in the opposite direction. The growth of the reaction zone is diffusion controlled and the mechanism of the reaction can be described by a reactive diffusion model of solid-state growth of an AmBn layer between two elementary substances A and B.展开更多
TiO2-hydroxyapatite （HA） nanostructured coatings were produced by atmospheric plasma spray method. The effects of starting powder composition and grain size on their mechanical properties were investigated. The micr...TiO2-hydroxyapatite （HA） nanostructured coatings were produced by atmospheric plasma spray method. The effects of starting powder composition and grain size on their mechanical properties were investigated. The microstructure and morphology were characterized by X-ray diffraction and scanning electron microscopy （SEM）. It is found that the coating with 10% HA has the best mechanical properties. Based on Rietveld refinement method, the mean grain size of the as-received powder （212 nm） extensively decreases to 66.4 nm after 20 h of high-energy ball milling. In spite of grain growth, the deposited coatings maintain their nanostructures with the mean grain size of 112 nm. SEM images show that there is a lower porosity in the coating with a higher HA content. Optical microscopy images show that uniform thickness is obtained for all the coatings.展开更多
Ti-Si-N composite coatings were synthesized on a novel combining cathode and middle-frequency magnetron sputtering system, designed on an industrial scale. Ti was produced from the arc target and Si from magnetron tar...Ti-Si-N composite coatings were synthesized on a novel combining cathode and middle-frequency magnetron sputtering system, designed on an industrial scale. Ti was produced from the arc target and Si from magnetron target during deposition. The influences of negative bias voltage and Si content on the hardness and microstructure of the coatings were investigated. The composite coatings prepared under optimized conditions were characterized to be nc-TiN/a-Si3N4 structure with grain sizes of TiN ranging from 8-15 nm and exhibited a high hardness of 40 GPa. The enhancement of the hardness is suggested to be caused by the nanograin-amorphous structure effects.展开更多
SiC_(f)/Ti composite owns the attractive advantages of lightweight and excellent high-temperature performance,which make it have great significance to the development of aerospace industry.However,the complicated fabr...SiC_(f)/Ti composite owns the attractive advantages of lightweight and excellent high-temperature performance,which make it have great significance to the development of aerospace industry.However,the complicated fabrication route and novel architecture of SiC_(f)/Ti composite bring about more difficulties for controlling its microstructure.In this work,the method of regulating the structure and performance of the composite matrix by adjusting the characteristics of the precursor wire was explored.The physical vapor deposition(PVD)method was applied to fabricate precursor wires.Ti6242 coatings with bamboo leaf-shaped grains and chrysanthemumshaped grains were deposited on SiC fibers by changing the PVD condition.It is found that the original structure of the Ti6242 coating of precursor wire has significant impact on the microstructure of the composite matrix after hot isostatic pressing(HIP).The matrix transformed from the Ti6242 coating with bamboo leaf-shaped grains exhibits equiaxed grain structure.While the other matrix has a columnar crystal structure,and the inside of the columnar crystal inherits the original chrysanthemum-shaped structure.The columnar crystal matrix has lower hardness and modulus than the equiaxed grain matrix.展开更多
文摘A series of single bcc,bcc plus fcc duplex and single fcc microcrystalline coatings of 1Cr18Ni9Ti stainless steel were prepared by using sputtering technique.The resistance against pitting corrosion was studied by measurements of pitting corrosion potentials and electrochemical noise during initiation of corrosion pits.The results show that the sputtered coatings with single bcc phase or single fcc structure are more resistant to pitting corrosion than those with bcc plus fcc duplex phase structure.
文摘Ti(C, N)-TiB2 composite coatings were deposited by means of reactive low pressure plasma spraying (LPPS) based on the technology of self-propagating high-temperature synthesis (SHS). The original powders were mixtures of Ti and B4C powders. The powders were mixed by ball mill and then spray-dried and at last sintered to be suitable for spraying. Two spraying distances were selected for LPPS. Scanning electron microscopy (SEM) was used to investigate the morphologies of powders for spraying and the microstructures of the coatings. The phase compositions of coatings were measured by X-ray diffraction (XRD). Spray-dried and sintered powders are denser and better bond than only spray-dried powders. The composite coating is composed of TiB2, TiC0.3N0.7, TiN0.3, Ti4N3-x and impurity phase of Ti5Si3 with 300 mm spraying distance. Partly unreacted B4C powders remained in the coating for 240 mm spraying distance, which may be inadequate reaction. No titanium oxide was detected in the composite coating for the relative high vacuum degree of LPPS. The anti-corrosion property of LPPS sprayed Ti(C, N)-TiB2 composite coating with 300 mm spraying distance in electrolytic solution is superior to that of 240 mm spraying distance. Microhardness of Ti(C, N)-TiB2 composite coating is relatively low due to the unconsolidated structure of the coating. The solving methods to improve property of composite coating are finally put forward in the paper.
文摘SiCf/Ti-6Al-4V composites were fabricated by the powder-coated fiber method. The precursor fiber was prepared under the optimized parameter, and the composites were made using the vacuum hot pressure method. The influence of heat exposure time on products of thelinterfacial reaction was investigated using scanning electron microscope （SEM） and analytical transmission electron microscope （TEM） with energy dispersive spectrometer （EDS）. The main products are TiC and Ti5Si3 after vacuum exposing the samples at 700℃ for 50 h. The growth dynamics of interracial reaction products was analyzed quantitatively, which fitted the parabola rule. The activity energy of the reaction was 252 kJ·mol^-1.
文摘The coating of Ni W P was deposited as base layer, and then the composite coating of Ni Ti(particles) Re(rare earth) was deposited subsequently on the surface of diamond using electroless plating by adding 2～3 μm Ti particles and trace rare earth salt to bath solution. Ti particles deposited on the surface of diamond were found by SEM and formation of TiC was verified by X ray diffraction analysis after heat treatment of the coatings in vacuum at 900 ℃. The binding strength between the coated diamond and the metal matrix was improved effectively in the diamond composite based on metal cement.
文摘Ti-Ni-Mo-Si composite coating was fabricated on mild steel by reactive braze coating process with Ti61. 9Ni24. 6Si4. 411409.1 （ wt. % ） powders as the raw materials. Microstr^cture of the coating was characterized by optical microscopy, scanning electron microscopy, X-ray diffraction and energy dispersive spectroscopy and micro-hardness tester. Results indicate that the Ti-Ni-Mo-Si composite coating is metallurgically bonded to the mild steel substrate and has high hardness. The microstructure of the coating consists of the reinforcement of Ti5 Si3 and Mo9 Ti4 particles and the matrix of eutectic NiTi2. Due to the poor wettability of NiTi2 liquid at low temperature, TisSi3 and Mo9 Ti4 do not uniformly distribute in the NiTi2 matrix.
文摘Metallization of the ceramic surfaces of Si3N4 and Al2O3 was carried out in a composite diffusion coating vacuum furnace using a Ti-Cu composite target. The experimental process and influencing factors were discussed. Optical microscope （OM） , energy dispersive spectroscopy （EDS） , scanning electron microscopy （SEM） , X-ray diffusion （XRD） and sound emissive scratch test （SEST） were applied to evaluate the alloy layer formed on the ceramic surface. It was indicated that the diffusion coating alloy layer contained Cu, Ti, Fe, Al and Si etc. XRD result indicated that the diffusion coating alloy layer was composed of CuTi2, Cu, Si2 Ti and CuTi, Al2 TiO5 , Ti3O5. It was found that the diffusion coating alloy layer got bonded with ceramic well, and no spaUation occurred under the maximum load of 100 N. Deposited Si3N4 ceramic was welded with Q235 and the joining quality was examined. Robust joint was formed between Si3N4 ceramic/Q235. This present method has advantages in high efficiency and low cost and provides a new approach for producing ceramic and metal bond.
文摘In this work, TiO2/Ti composite films were fabricated by 2-setp MCT and the following high temperature oxidation. Antibacterial activity of the composite films treated by ultrasonic cleaning to increase the performance reliability was examined. The prepared TiO2/Ti composite films showed high photocatalytic activity in the degradation of methylene blue solution. It is obvious that? TiO2/Ti composite films have antibacterial activity under UV irradiation.
文摘It is showed that there are Ti 3Al, Ti 2Cu and β phase in the interface of Ti/Ti Al composites reinforced with Y 2O 3 Cr composite soft coated Ti fiber, and that interface bonding is intact. Bending strength of the composites can be increased by 26%, to 709 MPa, and bending deflection increased slightly compared with the Ti/Ti Al composites reinforced by Ti fibers coated with Y 2O 3.
文摘A continuous loading push-out test technique was used to measure the interfacial shear strength of SiC fiber reinforced Ti matrix composites. The interfacial shear strength of samples as-fabricated and after heat exposed at 700 and 800℃ for 50 h was successfully determined. It has been found that the interfacial shear strength of the specimen exposed at 700℃ was higher than that of as-prepared and exposed samples at 800℃. The shear strength of the as-prepared samples was about 112.45 MPa, and increased to about 153.77 MPa after heat-treating at 700℃ for 50 h, but decreased to 133.11 MPa after treating at 800℃ for 50 h. Scanning electron microscope （SEM） was used to investigate the interfacial morphology of the samples. The brittle phase was the main products of interface for samples exposed at 800℃, and the interface was easily peeled off.
文摘In order to evaluate the interfacial reaction, a SiCf/Ti (TA1) composite was fabricated by a vacuum hot pressing method and then heat-treated in vacuum at 800℃ for up to 100 h. The elemental distributions of C, Si and Ti at the interfacial reaction zone were investigated. It was found that the reaction zone occurs during the fabrication process and continuously grows at high temperature because the Si and C atoms diffuse from SiC fibers to the matrix and Ti atoms diffuse in the opposite direction. The growth of the reaction zone is diffusion controlled and the mechanism of the reaction can be described by a reactive diffusion model of solid-state growth of an AmBn layer between two elementary substances A and B.
文摘TiO2-hydroxyapatite （HA） nanostructured coatings were produced by atmospheric plasma spray method. The effects of starting powder composition and grain size on their mechanical properties were investigated. The microstructure and morphology were characterized by X-ray diffraction and scanning electron microscopy （SEM）. It is found that the coating with 10% HA has the best mechanical properties. Based on Rietveld refinement method, the mean grain size of the as-received powder （212 nm） extensively decreases to 66.4 nm after 20 h of high-energy ball milling. In spite of grain growth, the deposited coatings maintain their nanostructures with the mean grain size of 112 nm. SEM images show that there is a lower porosity in the coating with a higher HA content. Optical microscopy images show that uniform thickness is obtained for all the coatings.
基金Funded by the Natural Science Foundation of China(No.10435060 andNo. 10675095)
文摘Ti-Si-N composite coatings were synthesized on a novel combining cathode and middle-frequency magnetron sputtering system, designed on an industrial scale. Ti was produced from the arc target and Si from magnetron target during deposition. The influences of negative bias voltage and Si content on the hardness and microstructure of the coatings were investigated. The composite coatings prepared under optimized conditions were characterized to be nc-TiN/a-Si3N4 structure with grain sizes of TiN ranging from 8-15 nm and exhibited a high hardness of 40 GPa. The enhancement of the hardness is suggested to be caused by the nanograin-amorphous structure effects.
基金financially supported by the Key Laboratory Foundation of China(No.61429040301)。
文摘SiC_(f)/Ti composite owns the attractive advantages of lightweight and excellent high-temperature performance,which make it have great significance to the development of aerospace industry.However,the complicated fabrication route and novel architecture of SiC_(f)/Ti composite bring about more difficulties for controlling its microstructure.In this work,the method of regulating the structure and performance of the composite matrix by adjusting the characteristics of the precursor wire was explored.The physical vapor deposition(PVD)method was applied to fabricate precursor wires.Ti6242 coatings with bamboo leaf-shaped grains and chrysanthemumshaped grains were deposited on SiC fibers by changing the PVD condition.It is found that the original structure of the Ti6242 coating of precursor wire has significant impact on the microstructure of the composite matrix after hot isostatic pressing(HIP).The matrix transformed from the Ti6242 coating with bamboo leaf-shaped grains exhibits equiaxed grain structure.While the other matrix has a columnar crystal structure,and the inside of the columnar crystal inherits the original chrysanthemum-shaped structure.The columnar crystal matrix has lower hardness and modulus than the equiaxed grain matrix.
基金Project(LQ21E040004) supported by the Natural Science Foundation of Zhejiang Province,ChinaProject(2021-Z03) supported by the State Key Laboratory of Advanced Metals and Materials,China。
