Design a precision electroplating mechanical structure for automobiles based on finite element analysis method and analyze its mechanical properties.Taking the automobile steering knuckle as the research object,ABAQUS...Design a precision electroplating mechanical structure for automobiles based on finite element analysis method and analyze its mechanical properties.Taking the automobile steering knuckle as the research object,ABAQUS parametric modeling technology is used to construct its three-dimensional geometric model,and geometric simplification is carried out.Two surface treatment processes,HK-35 zinc nickel alloy electroplating and pure zinc electroplating,were designed,and the influence of different coatings on the mechanical properties of steering knuckles was compared and analyzed through numerical simulation.At the same time,standard specimens were prepared for salt spray corrosion testing and scratch method combined strength testing to verify the numerical simulation results.The results showed that under emergency braking and composite working conditions,the peak Von Mises stress of the zinc nickel alloy coating was 119.85 MPa,which was lower than that of the pure zinc coating and the alkaline electroplated zinc layer.Its equivalent strain value was 652×10^(-6),which was lower than that of the pure zinc coating and the alkaline electroplated zinc layer.Experimental data confirms that zinc nickel alloy coatings exhibit significant advantages in stress distribution uniformity,strain performance,and load-bearing capacity in high stress zones.The salt spray corrosion test further indicates that the coating has superior corrosion resistance and coating substrate interface bonding strength,which can significantly improve the mechanical stability and long-term reliability of automotive precision electroplating mechanical structures.展开更多
The cathodic deposition properties and mechanism of Zn in alkaline zincate solution were studied by electrochemical techniques. The results show that Zn2+ exists in the alkaline solution in the form of Zn(OH)42-. The ...The cathodic deposition properties and mechanism of Zn in alkaline zincate solution were studied by electrochemical techniques. The results show that Zn2+ exists in the alkaline solution in the form of Zn(OH)42-. The apparent activation energy of the electrode reaction is 38.93 kJ/mol, which indicates that the discharge of Zn(OH)42- on cathode is controlled by electrochemical polarization, and accompanied by a preceding chemical reaction. The diffusion coefficient of Zn(OH)42- is 2.452×10-6 cm2/s. Zn(OH)2 is the species directly discharged on the cathode surface. Based on the above results the mechanism of zinc electroplating in alkaline zincate solution was put forward. The discharged species is Zn(OH)2 formed from the preceding chemical reaction, which becomes Zn(OH)ad when gaining one electron, and then gaining the second electron to become Zn. The first electron gaining step is rate determining one.展开更多
To degrade the organic compounds in the electroplating wastewater,magnetic field was tentatively introduced into electrocatalytic oxidation on Ti-PbO2 anode.The magnetic field assisted electrocatalytic oxidation can p...To degrade the organic compounds in the electroplating wastewater,magnetic field was tentatively introduced into electrocatalytic oxidation on Ti-PbO2 anode.The magnetic field assisted electrocatalytic oxidation can promote anion movement and the generation of active species,resulting more organic compounds to be oxidized and degraded.Oxidation parameters such as treatment time,current density and initial pH of the wastewater were systematically discussed and optimized.The mineralization of organic compounds is improved by over 15% under a magnetic density of 22 mT while the current density is 50 A/m2,pH is 1.8 and the reaction time is 1.5 h.The results indicate that the magnetic field assisted electrocatalytic oxidation has considerable potential in electroplating wastewater treatment.展开更多
Iron-plating technology used for restoration of axis parts was applied to the manufacture of diamond bits in this paper.The technology for electroplating diamond bit of iron matrix was mastered through repeated experi...Iron-plating technology used for restoration of axis parts was applied to the manufacture of diamond bits in this paper.The technology for electroplating diamond bit of iron matrix was mastered through repeated experiments and research.The productive practice indicated that the DC-electroplated iron matrix of diamond bit has high hardness and good diamond exposure ability;the drilling rate of electroplated iron-based diamond bit was 2 m/h when drilling in grade 9 granite and bit life can reach 44 m,which can satisfy the drilling production requirements.展开更多
The effect of hydrogen inhibitor on partial current densities ofZn, Fe and differential capacitance of electrode/electrolyte interface, and adsorbing type of hydrogen inhibitor were studied by the methods of electroch...The effect of hydrogen inhibitor on partial current densities ofZn, Fe and differential capacitance of electrode/electrolyte interface, and adsorbing type of hydrogen inhibitor were studied by the methods of electrochemistry. The mechanism of current efficiency improvement were explained from the point of valence electron theory. The results indicate that the partial current density of Fe increases in addition of hydrogen inhibitor, which reaches the maximum of 0.14 A/dm^2 when current density is 0.2 A/din〈 Differential capacitance of electrode/electrolyte interface decreases obviously from 20.3μF/cm^2 to 7 μF/cm^2 rapidly with the concentration varying from 0 to 20 mL/L, because hydrogen inhibitor chemically adsorbs on active points of Fe electrode surface selectively. Element S in hydrogen inhibitor with negative electricity and strong capacity of offering electron shares isolated electrons with Fe. The adsorption of H atom is inhibited when adsorbing on active points of Fe electrode surface firstly, and then current efficiency of Zn-Fe alloy electroplating is improved accordingly.展开更多
Electroplating is a process using electric current to deposit a layer of metal(s),which is an indispensable technique in the manufacture of integrated circuits and micro-nano electronic devices.Electroplating for mode...Electroplating is a process using electric current to deposit a layer of metal(s),which is an indispensable technique in the manufacture of integrated circuits and micro-nano electronic devices.Electroplating for modern electronics is much smaller in scale than the ordinary electroplating processes and relies heavily on foreign technique,such as proprietary materials and equipment.As the competition in the field of chip manufacture intensifies,we realize that there is no choice but to become self-sufficient in such technology,including,but not limited to electroplating technology.展开更多
Electroplating is a process using electric current to deposit a layer of metal(s),which is an indispensable technique in the manufacture of integrated circuits and micro-nano electronic devices.Electroplating for mode...Electroplating is a process using electric current to deposit a layer of metal(s),which is an indispensable technique in the manufacture of integrated circuits and micro-nano electronic devices.Electroplating for modern electronics is much smaller in scale than the ordinary electroplating processes and relies heavily on foreign technique,such as proprietary materials and equipment.As the competition in the field of chip manufacture intensifies,we realize that there is no choice but to become self-sufficient in such technology,including,but not limited to electroplating technology.展开更多
0 Introduction Economy and the protection of the environment are important topics.We are competent to talk about these topics.Due to the expanding areas of application for highprecision and electroplated diamond tools...0 Introduction Economy and the protection of the environment are important topics.We are competent to talk about these topics.Due to the expanding areas of application for highprecision and electroplated diamond tools with reproducible quality and long life,of course the aspects of economy and environmental protection gain increasing significance.In this lecture we will explain and show that economical aspects and environmental aspects in diamond electro-plating do not contradict,but rather complement each other.展开更多
Ni-P/SiC/PTFE coating was obtained on the surface of 316L stainless steel by electrodeposition of Ni-P/SiC coating and immersion of PTFE(polytetrafluoroethylene).The surface morphology and composition were analyzed by...Ni-P/SiC/PTFE coating was obtained on the surface of 316L stainless steel by electrodeposition of Ni-P/SiC coating and immersion of PTFE(polytetrafluoroethylene).The surface morphology and composition were analyzed by scanning electron microscope and energy dispersive spectrometer.The corrosion resistance of the coating in 0.5 mol/L H2SO4+2×10−6 HF solution was studied by electrochemical method.Surface contact angle was used to test the hydrophobic properties of the coating.The results indicated that the Ni-P/SiC/PTFE coating prepared on the surface of stainless steel was uniform and compact,which significantly improved the self-corrosion potential of stainless steel.The self-corrosion current density decreased from 7.62 to 0.008μA/cm2.The durability performance of coating was tested under 0.6 V voltage and the stable corrosion current density value was 0.19μA/cm2,then wetting angle was tested after durability experiment and the value is 134.5°.展开更多
The intermediate layer was prepared by nickel doped with WC particles electroplating.The parameters,including current density and temperature,were studied.The measured methods,which consisted of surface roughometer an...The intermediate layer was prepared by nickel doped with WC particles electroplating.The parameters,including current density and temperature,were studied.The measured methods,which consisted of surface roughometer and SEM,were used to character the roughness and micrograph.Based on the results,it was shown that the optimized parameters of the composite were as follows,temperature 65 ℃,current density 5 A/dm2 and pH 6.5.In the range of optimized parameters,the roughness Ra was from 4.5 to 6.7 μm.From the SEM micrograph,the particles on the surface were well distributed.The nickel content,which affected the binding force,was determined by the electroplating time.展开更多
Sand-wear resistance of nano scale alumina particle reinforced nickel matrix composite coating （n-Al2O3/Ni） prepared by brush electroplating technique was investigated via wear tests in sand-contaminated oil lubrica...Sand-wear resistance of nano scale alumina particle reinforced nickel matrix composite coating （n-Al2O3/Ni） prepared by brush electroplating technique was investigated via wear tests in sand-contaminated oil lubricant, comparing with that of AISI1045 steel and brush electroplated Ni coating. Effects of testing load, sand content and sand size on worn volume of the three materials, and also coating surface roughness on worn volume of the brush electroplated coatings were accessed. Results show that the worn volume of all the three materials increases with increasing of testing load, sand content and sand size. In the same conditions, n-Al2O3/Ni composite coating has the smallest worn volume while AISI1045 steel has the largest because of the n-Al2O3 particle effects. As to n-Al2O3/Ni and Ni coatings, the surface-polished coatings have obviously lower worn volume than the as-plated coatings. The brush electroplated n-Al2O3/Ni composite coating was employed to remanufacture the sand-worn bearing seats of a heavy vehicle and good results were gained.展开更多
Based on impulse and vibration machining theories,a mathematical model of cutting force for the electroplated diamond ultrasonic wire saw was established using superposition principle.The differences between the cutti...Based on impulse and vibration machining theories,a mathematical model of cutting force for the electroplated diamond ultrasonic wire saw was established using superposition principle.The differences between the cutting forces with and without ultrasonic effect were analyzed theoretically and experimentally.The results indicate that the cutting force of diamond wire increases along with the spindle speed decrease and the lateral pressure increase.The force in ultrasonic vibration cutting is about 20% to 30% less than that in conventional cutting.Also,the cutting trajectory of single diamond grit in sawing process is simulated,and the reason that the ultrasonic vibration can reduce the cutting force is explained further.展开更多
The cutting process of electroplated diamond wire saw was researched on the basis of impulse and vibration machining theories. The different contact states in the cutting process were analyzed by using the finite elem...The cutting process of electroplated diamond wire saw was researched on the basis of impulse and vibration machining theories. The different contact states in the cutting process were analyzed by using the finite element method. It shows that the cutting stress is uniformly distributed along the direction of the workpiece width in the steady state. A mathematical equation of sawing trajectory was established by using the superposition principle and the cutting experiment of wire saw to calculate the cutting trajectory. The comparison of the theoretical trajectory with the calculated one indicates that the error is less than 15%. The research results provide a theoretic basis for optimization of the saw's cutting process parameters.展开更多
文摘Design a precision electroplating mechanical structure for automobiles based on finite element analysis method and analyze its mechanical properties.Taking the automobile steering knuckle as the research object,ABAQUS parametric modeling technology is used to construct its three-dimensional geometric model,and geometric simplification is carried out.Two surface treatment processes,HK-35 zinc nickel alloy electroplating and pure zinc electroplating,were designed,and the influence of different coatings on the mechanical properties of steering knuckles was compared and analyzed through numerical simulation.At the same time,standard specimens were prepared for salt spray corrosion testing and scratch method combined strength testing to verify the numerical simulation results.The results showed that under emergency braking and composite working conditions,the peak Von Mises stress of the zinc nickel alloy coating was 119.85 MPa,which was lower than that of the pure zinc coating and the alkaline electroplated zinc layer.Its equivalent strain value was 652×10^(-6),which was lower than that of the pure zinc coating and the alkaline electroplated zinc layer.Experimental data confirms that zinc nickel alloy coatings exhibit significant advantages in stress distribution uniformity,strain performance,and load-bearing capacity in high stress zones.The salt spray corrosion test further indicates that the coating has superior corrosion resistance and coating substrate interface bonding strength,which can significantly improve the mechanical stability and long-term reliability of automotive precision electroplating mechanical structures.
基金Project(50274073) supported by the National Natural Science Foundation of China
文摘The cathodic deposition properties and mechanism of Zn in alkaline zincate solution were studied by electrochemical techniques. The results show that Zn2+ exists in the alkaline solution in the form of Zn(OH)42-. The apparent activation energy of the electrode reaction is 38.93 kJ/mol, which indicates that the discharge of Zn(OH)42- on cathode is controlled by electrochemical polarization, and accompanied by a preceding chemical reaction. The diffusion coefficient of Zn(OH)42- is 2.452×10-6 cm2/s. Zn(OH)2 is the species directly discharged on the cathode surface. Based on the above results the mechanism of zinc electroplating in alkaline zincate solution was put forward. The discharged species is Zn(OH)2 formed from the preceding chemical reaction, which becomes Zn(OH)ad when gaining one electron, and then gaining the second electron to become Zn. The first electron gaining step is rate determining one.
基金Project(2008ZX07101-006-09) supported by the Major Science and Technology Program for Water Pollution Control and Treatment of China
文摘To degrade the organic compounds in the electroplating wastewater,magnetic field was tentatively introduced into electrocatalytic oxidation on Ti-PbO2 anode.The magnetic field assisted electrocatalytic oxidation can promote anion movement and the generation of active species,resulting more organic compounds to be oxidized and degraded.Oxidation parameters such as treatment time,current density and initial pH of the wastewater were systematically discussed and optimized.The mineralization of organic compounds is improved by over 15% under a magnetic density of 22 mT while the current density is 50 A/m2,pH is 1.8 and the reaction time is 1.5 h.The results indicate that the magnetic field assisted electrocatalytic oxidation has considerable potential in electroplating wastewater treatment.
文摘Iron-plating technology used for restoration of axis parts was applied to the manufacture of diamond bits in this paper.The technology for electroplating diamond bit of iron matrix was mastered through repeated experiments and research.The productive practice indicated that the DC-electroplated iron matrix of diamond bit has high hardness and good diamond exposure ability;the drilling rate of electroplated iron-based diamond bit was 2 m/h when drilling in grade 9 granite and bit life can reach 44 m,which can satisfy the drilling production requirements.
基金Projects(50274073) supported by the National Natural Science Foundation of China
文摘The effect of hydrogen inhibitor on partial current densities ofZn, Fe and differential capacitance of electrode/electrolyte interface, and adsorbing type of hydrogen inhibitor were studied by the methods of electrochemistry. The mechanism of current efficiency improvement were explained from the point of valence electron theory. The results indicate that the partial current density of Fe increases in addition of hydrogen inhibitor, which reaches the maximum of 0.14 A/dm^2 when current density is 0.2 A/din〈 Differential capacitance of electrode/electrolyte interface decreases obviously from 20.3μF/cm^2 to 7 μF/cm^2 rapidly with the concentration varying from 0 to 20 mL/L, because hydrogen inhibitor chemically adsorbs on active points of Fe electrode surface selectively. Element S in hydrogen inhibitor with negative electricity and strong capacity of offering electron shares isolated electrons with Fe. The adsorption of H atom is inhibited when adsorbing on active points of Fe electrode surface firstly, and then current efficiency of Zn-Fe alloy electroplating is improved accordingly.
文摘Electroplating is a process using electric current to deposit a layer of metal(s),which is an indispensable technique in the manufacture of integrated circuits and micro-nano electronic devices.Electroplating for modern electronics is much smaller in scale than the ordinary electroplating processes and relies heavily on foreign technique,such as proprietary materials and equipment.As the competition in the field of chip manufacture intensifies,we realize that there is no choice but to become self-sufficient in such technology,including,but not limited to electroplating technology.
文摘Electroplating is a process using electric current to deposit a layer of metal(s),which is an indispensable technique in the manufacture of integrated circuits and micro-nano electronic devices.Electroplating for modern electronics is much smaller in scale than the ordinary electroplating processes and relies heavily on foreign technique,such as proprietary materials and equipment.As the competition in the field of chip manufacture intensifies,we realize that there is no choice but to become self-sufficient in such technology,including,but not limited to electroplating technology.
文摘0 Introduction Economy and the protection of the environment are important topics.We are competent to talk about these topics.Due to the expanding areas of application for highprecision and electroplated diamond tools with reproducible quality and long life,of course the aspects of economy and environmental protection gain increasing significance.In this lecture we will explain and show that economical aspects and environmental aspects in diamond electro-plating do not contradict,but rather complement each other.
基金Project(2018YFB1502500)supported by the National Key Research and Development Program of ChinaProject supported by State Key Laboratory of Powder Metallurgy,Central South University,China+1 种基金Projects(2020JJ5100,2018JJ3101)supported by Natural Science Foundation of Hunan Province,ChinaProject(51671085)supported by the National Natural Science Foundation of China。
文摘Ni-P/SiC/PTFE coating was obtained on the surface of 316L stainless steel by electrodeposition of Ni-P/SiC coating and immersion of PTFE(polytetrafluoroethylene).The surface morphology and composition were analyzed by scanning electron microscope and energy dispersive spectrometer.The corrosion resistance of the coating in 0.5 mol/L H2SO4+2×10−6 HF solution was studied by electrochemical method.Surface contact angle was used to test the hydrophobic properties of the coating.The results indicated that the Ni-P/SiC/PTFE coating prepared on the surface of stainless steel was uniform and compact,which significantly improved the self-corrosion potential of stainless steel.The self-corrosion current density decreased from 7.62 to 0.008μA/cm2.The durability performance of coating was tested under 0.6 V voltage and the stable corrosion current density value was 0.19μA/cm2,then wetting angle was tested after durability experiment and the value is 134.5°.
文摘The intermediate layer was prepared by nickel doped with WC particles electroplating.The parameters,including current density and temperature,were studied.The measured methods,which consisted of surface roughometer and SEM,were used to character the roughness and micrograph.Based on the results,it was shown that the optimized parameters of the composite were as follows,temperature 65 ℃,current density 5 A/dm2 and pH 6.5.In the range of optimized parameters,the roughness Ra was from 4.5 to 6.7 μm.From the SEM micrograph,the particles on the surface were well distributed.The nickel content,which affected the binding force,was determined by the electroplating time.
文摘Sand-wear resistance of nano scale alumina particle reinforced nickel matrix composite coating （n-Al2O3/Ni） prepared by brush electroplating technique was investigated via wear tests in sand-contaminated oil lubricant, comparing with that of AISI1045 steel and brush electroplated Ni coating. Effects of testing load, sand content and sand size on worn volume of the three materials, and also coating surface roughness on worn volume of the brush electroplated coatings were accessed. Results show that the worn volume of all the three materials increases with increasing of testing load, sand content and sand size. In the same conditions, n-Al2O3/Ni composite coating has the smallest worn volume while AISI1045 steel has the largest because of the n-Al2O3 particle effects. As to n-Al2O3/Ni and Ni coatings, the surface-polished coatings have obviously lower worn volume than the as-plated coatings. The brush electroplated n-Al2O3/Ni composite coating was employed to remanufacture the sand-worn bearing seats of a heavy vehicle and good results were gained.
基金Sponsored by Liaoning Innovation Team Fundation(2008T164)
文摘Based on impulse and vibration machining theories,a mathematical model of cutting force for the electroplated diamond ultrasonic wire saw was established using superposition principle.The differences between the cutting forces with and without ultrasonic effect were analyzed theoretically and experimentally.The results indicate that the cutting force of diamond wire increases along with the spindle speed decrease and the lateral pressure increase.The force in ultrasonic vibration cutting is about 20% to 30% less than that in conventional cutting.Also,the cutting trajectory of single diamond grit in sawing process is simulated,and the reason that the ultrasonic vibration can reduce the cutting force is explained further.
基金Sponsored by Innovation team item fund of Liaoning Province ( 2008T164)
文摘The cutting process of electroplated diamond wire saw was researched on the basis of impulse and vibration machining theories. The different contact states in the cutting process were analyzed by using the finite element method. It shows that the cutting stress is uniformly distributed along the direction of the workpiece width in the steady state. A mathematical equation of sawing trajectory was established by using the superposition principle and the cutting experiment of wire saw to calculate the cutting trajectory. The comparison of the theoretical trajectory with the calculated one indicates that the error is less than 15%. The research results provide a theoretic basis for optimization of the saw's cutting process parameters.
