A novel sensor for ocean electric field testing has been fabricated by polyacrylonitrile-based on carbon fibers with electro-chemical oxidation.The surface profile characteristics of the carbon fibers were characteriz...A novel sensor for ocean electric field testing has been fabricated by polyacrylonitrile-based on carbon fibers with electro-chemical oxidation.The surface profile characteristics of the carbon fibers were characterized by scanning electron microscope,Fourier transform infrared spectra and contact angle.Cyclic voltammetry and Tafel curves have been used to study its electro-chemical performances.Two identical electrodes in sea water as the electric field sensor will swiftly respond to applied electric field which causes positive and negative ions to move in opposite direction,resulting in a electric potential difference(ΔE).Test result indicates that the offset potential is typically below 1 m V with a drift of 60-170μVd^-1.Typical self noise level is 1.07 nV√Hz^(1/2)@1 Hz.The electric field response indicates that the modified electrode pair shows better response to AC sine signal of amplitude and frequency(5 mV and 1 mHz)respectively than its blank.The electric field response model of the modified electrodes is creatively presented according to its electric double layer capacitance and Faraday pseudo-capacitance.Many advantages of the carbon fiber electric field electrode will make it have potential application prospect.展开更多
A new idea for designing wheel patterns is presented so as to solve theproblems about machining accuracy of workpiece and wear of honing wheel in ultra-precision planehoning. The influence factors on motion principle ...A new idea for designing wheel patterns is presented so as to solve theproblems about machining accuracy of workpiece and wear of honing wheel in ultra-precision planehoning. The influence factors on motion principle and pattern structures are analyzed andoptimization machining parameters are obtained. By calculating effective cutting length on thesurface of workpiece cut by wheel's abrasive and the orbit of one point on the surface of workpiececontacting with wheel, the wear coefficient of different kinds of wheels and accuracy coefficient ofworkpiece machined by corresponding wheels are obtained. Furthermore, the simulation results showthat the optimal pattern structure of wheel turns out to have lower wheel wear and higher machiningaccuracy.展开更多
In 1982, Professor Fang Guoliang found the "Non full resonance" phenomenon in a tool system while he use the thin-long tool ultrasonically machining deep-small hole. He called it as "local resonance&quo...In 1982, Professor Fang Guoliang found the "Non full resonance" phenomenon in a tool system while he use the thin-long tool ultrasonically machining deep-small hole. He called it as "local resonance". Also this "Non full resonance" phenomenon was discovered in the ultrasonic drilling and the ultrasonic honing system later. To its mechanism, professor Fang thought that the coupling of long-thin tool bar and driving system is weak, so the tool bar can vibrate independently, but the quantitative relation between the coupling factor and diameter ratio is not made certain. Then several theories come forth to interpret it but still haven’t a common conclusion. Through the systematic experimental and theoretical research, this paper reveals that the "local resonance" phenomenon of ultrasonic honing system has the same essence with the "local resonance" phenomenon in deep hole machining system: when the section area ratio of tool bar and driving system is small enough, some resonance frequencies of combined system are close to the resonance frequencies of "fixed-free" state tool bar, the combined system is still resonant. According to the given depth of hole and structure size, we can use the transfer matrix deduced in this paper to design flexible bar and oilstone seat not only satisfying mechanical structure size but also achieving enough magnitude. It greatly simplified the design. This new method can be named as "local resonance" design method for ultrasonic honing system. The experiment, deduction and design method have a certain common meaning to the study and design of other ultrasonic system.展开更多
The objective of this work is to compare the tool performance of TiN and TiAlN coated carbides end-mills deposited by an arc ion plating (AIP) method, using honing treatment to polish the cutting edge surface sleekly....The objective of this work is to compare the tool performance of TiN and TiAlN coated carbides end-mills deposited by an arc ion plating (AIP) method, using honing treatment to polish the cutting edge surface sleekly. The curve of surface roughness versus honing time showed a rapid improvement initially and thereafter became steady, manifesting a saturation effect. The optimal honing time related to surface roughness was determined to be approximately 20 s. As the surface roughness increased, the critical loads reduced. At an average surface roughness (Ra) of 0.028 μm, the highest critical loads of TiN and TiAlN coating layers were 98 and 114 N, respectively. Tool performances of uncoated and coated tools were conducted under high speed machining (HSM) of AISI D2 cold-worked die steel (62 HRC). Consequently, the TiAlN coated end-mill using honing treatment showed excellent tool life under HSM conditions.展开更多
Free abrasive particle machining in simple machine such as: honing, polishing can get higher surface finish mirror, but surface error, and working procedure is hard to control. Therefore, the vertical disposed ultra-p...Free abrasive particle machining in simple machine such as: honing, polishing can get higher surface finish mirror, but surface error, and working procedure is hard to control. Therefore, the vertical disposed ultra-precision plane honing method by ultra-particle diamond honing wheel is put forward to. The results of experiments indicate: plane-honing wheel has higher machining accuracy and machining efficiency. But at the same time the structure parameters of honing wheel effects on machining accuracy. By analyzing the relation of honing wheel structure parameters and workpiece machining accuracy, the relation of honing wheel and wear coefficient, then this paper gets honing wheel structure parameters in the condition of best accuracy coefficient and wear coefficient, and resolve the problem of choosing honing wheel structure parameters in ultra-precision plane honing at last. This paper analyses the relation of honing wheel structure parameters and workpiece machining accuracy coefficient and wear coefficient, by building relative movement math model of honing wheel and workpiece in plane honing. Through theory calculating, the result indicate: about honing machine tools for large volume manufacture, honing wheel wear is main effect factor, so honing wheel should adopt obverse triangle radial structure. About honing machining for high accuracy and low-batch quantities, machining accuracy coefficient is main factors; so honing wheel should adopt reverse triangle radial structure. Neglected the manufacturing factors of honing wheel, then we can design honing wheel with high power curve structure to meet the need of machining accuracy coefficient and honing wheel wear coefficient in higher accuracy honing.展开更多
The removal mechanism is of importance to the grinding of hard and brittle ceramic materials. It is more suitable to analyze the material removal during ceramics honing processes by means of indention fracture approac...The removal mechanism is of importance to the grinding of hard and brittle ceramic materials. It is more suitable to analyze the material removal during ceramics honing processes by means of indention fracture approach. There are two honing characteristics different from grinding, the honing incidental tensile stresses and the crosshatch pattern. The stresses may influence material removal of brittle ceramics with lower tensile strength. In addition, the criss-cross cutting pattern on a bore known as crosshatch may also have its effect on the material removal of ceramics. The material removal of alumina is analyzed on the basis of honing characteristics, honing incidental tensile stresses and crosshatch pattern. By means of indentation fracture mechanics of brittle solids, the theoretical analysis of stress intensity factor and the crack response prove that honing incidental tensile stresses can increase the stress intensity factor of honing cracks and decrease the grinding stresses. So, the fracture criterion for crack propagation can be met easily. Therfore, it is possible to machine ceramic materials with small grinding forces in honing processes. The alumina honing experiments show that material at crosshatch intersecting point is removed by way of chipping which is similar to the edge-crumbled of ceramics. For brittle ceramics with lower tensile strength, such as Al 2O 3, SiO 2, the influences of the honing incidental tensile stresses and the crosshatch pattern on material removal are bigger than that of ceramics with relative higher toughness, such as ZrO 2 and Si 3N 4. Hence, the honing of Al 2O 3, SiO 2, is superior in cutting ability to the grinding. The large stock removal of brittle ceramic materials can be obtained through higher honing pressures. The increase in honing pressures can increase intensity factor of honing cracks, decrease the grinding stresses, and remarkably improve material removal rate. The researches show that honing is an efficient bore machining operation for brittle ceramics.展开更多
In recent years, the new technology of ultrasonic vibration cutting has been drawing general attention. And great advancement in theory and applications in production of the technology have been achieved. Ultrasonic v...In recent years, the new technology of ultrasonic vibration cutting has been drawing general attention. And great advancement in theory and applications in production of the technology have been achieved. Ultrasonic vibration honing system developed in North China Institute of Technology and Nanjing University of Aeronautics and Astronautics of cast iron cylinder (47×97) and thin cylinder of 20# (86×95) has been successfully applied to productive experiment and the technological effect obtained is ideal. In comparison with ordinary honing, ultrasonic vibration honing possesses apparent characteristics: Firstly, it has high processing precision (precision in size ranks IT6, roughness Ra0.05, circularty and cylindericity in size ranks IT6); Secondly, it has small cutting force and low temperature so that no deformation occurs; Thirdly, it has high efficiency. In this paper, the application of a new technique to honing is introduced, and the ultrasonic honing systems of thin cylinder and cast cylinder which have been successfully manufactured and their applying effect are illustrated. This paper analyzes the cutting principle of ultrasonic honing in terms of cutting motion, grain performance and cutting quantity. The study of this technique starts a new approach to which is efficient higher quality and lower consumption to hole’s precise and superprecise machining. At last,the paper introduce the conclution: Ultrasonic honing sharpens grain, which is favorable for raising cutting efficiency; Ultrasonic vibration honing may increase honing depth and raise cutting efficiency. It may also decrease honing power and system deformation; Undergoing practice we can find that the ultrasonic honing system as above discribed can be extended and applied to production. The system not only can be applied to conventional honing machine, its technology effect as good as high precision machine tool, but also can be applied to develop and study ultrasonic vibrating numbrical controlling honing machine tool which will provide a new type, efficient, high quality low consumption, equipment for working precision hole; Appling the same parament as W40 oilstone bar, under the same condition, is very valuable for product and application. Rough machining and finish machining once time finished, which not only improve location accuracy, but also have a high effiency.The honing system not only can be suitable for honing cast cylinder, but also can be applied for honing engineer ceramics as well as hard, crisp material; The dimension and technology paraments of 47 mm honing system as above discribed, can be suitable for honing the cast cylinder of motorcycle or minicar. And the cylinder diameter can be randomly selected from 45 to 65. The dimension and technology paramagnets of 86 honing system as above discribed,can be applied for honing all kinds of cylinder of light or heavy passenger-cargo vehicle, and the cylinder diameter can be randomly selected from 65 to 100; It is easy to achieve new technology of flat roof honing by applying ultrasonic honing.After the flat roof honing, fuel consumption of engine is 1g/Hp, while conventional engine is 3g/Hp.Life expectancy of engine is prolonged greatly after the cylinder by flat roof honing.展开更多
In reality,it is easier and better to be honest.One of my favourite,and least favourite characteristics of my Chinese friends is that they are extremely honest.In the West,we spend a lot of time being extremely care-f...In reality,it is easier and better to be honest.One of my favourite,and least favourite characteristics of my Chinese friends is that they are extremely honest.In the West,we spend a lot of time being extremely care-ful what we say to each other,and we also like to make sure that we are always展开更多
ANIMAL husbandry technician Vasco Silva always found it difficult to master the technology applied to artificial insemination （AI） of cattle. However, in December last year. a training course changed the Mozambican...ANIMAL husbandry technician Vasco Silva always found it difficult to master the technology applied to artificial insemination （AI） of cattle. However, in December last year. a training course changed the Mozambican＇s original thought of the technology and the way it is used,展开更多
基金supported by the National Defense Science and Technology Innovation Zone Project(No.18-H863-05-ZT-001-018-09)
文摘A novel sensor for ocean electric field testing has been fabricated by polyacrylonitrile-based on carbon fibers with electro-chemical oxidation.The surface profile characteristics of the carbon fibers were characterized by scanning electron microscope,Fourier transform infrared spectra and contact angle.Cyclic voltammetry and Tafel curves have been used to study its electro-chemical performances.Two identical electrodes in sea water as the electric field sensor will swiftly respond to applied electric field which causes positive and negative ions to move in opposite direction,resulting in a electric potential difference(ΔE).Test result indicates that the offset potential is typically below 1 m V with a drift of 60-170μVd^-1.Typical self noise level is 1.07 nV√Hz^(1/2)@1 Hz.The electric field response indicates that the modified electrode pair shows better response to AC sine signal of amplitude and frequency(5 mV and 1 mHz)respectively than its blank.The electric field response model of the modified electrodes is creatively presented according to its electric double layer capacitance and Faraday pseudo-capacitance.Many advantages of the carbon fiber electric field electrode will make it have potential application prospect.
基金This project is supported by Foundation of Xiamen Univer sity of China for Scholars Return from Abroad (No.08003).
文摘A new idea for designing wheel patterns is presented so as to solve theproblems about machining accuracy of workpiece and wear of honing wheel in ultra-precision planehoning. The influence factors on motion principle and pattern structures are analyzed andoptimization machining parameters are obtained. By calculating effective cutting length on thesurface of workpiece cut by wheel's abrasive and the orbit of one point on the surface of workpiececontacting with wheel, the wear coefficient of different kinds of wheels and accuracy coefficient ofworkpiece machined by corresponding wheels are obtained. Furthermore, the simulation results showthat the optimal pattern structure of wheel turns out to have lower wheel wear and higher machiningaccuracy.
文摘In 1982, Professor Fang Guoliang found the "Non full resonance" phenomenon in a tool system while he use the thin-long tool ultrasonically machining deep-small hole. He called it as "local resonance". Also this "Non full resonance" phenomenon was discovered in the ultrasonic drilling and the ultrasonic honing system later. To its mechanism, professor Fang thought that the coupling of long-thin tool bar and driving system is weak, so the tool bar can vibrate independently, but the quantitative relation between the coupling factor and diameter ratio is not made certain. Then several theories come forth to interpret it but still haven’t a common conclusion. Through the systematic experimental and theoretical research, this paper reveals that the "local resonance" phenomenon of ultrasonic honing system has the same essence with the "local resonance" phenomenon in deep hole machining system: when the section area ratio of tool bar and driving system is small enough, some resonance frequencies of combined system are close to the resonance frequencies of "fixed-free" state tool bar, the combined system is still resonant. According to the given depth of hole and structure size, we can use the transfer matrix deduced in this paper to design flexible bar and oilstone seat not only satisfying mechanical structure size but also achieving enough magnitude. It greatly simplified the design. This new method can be named as "local resonance" design method for ultrasonic honing system. The experiment, deduction and design method have a certain common meaning to the study and design of other ultrasonic system.
基金Project(2010-0008-277) supported by NCRC Program through the National Research Foundation of Korea funded by the Ministry of Education, Science and TechnologyProject supported by Pusan National University Research Grant, Korea
文摘The objective of this work is to compare the tool performance of TiN and TiAlN coated carbides end-mills deposited by an arc ion plating (AIP) method, using honing treatment to polish the cutting edge surface sleekly. The curve of surface roughness versus honing time showed a rapid improvement initially and thereafter became steady, manifesting a saturation effect. The optimal honing time related to surface roughness was determined to be approximately 20 s. As the surface roughness increased, the critical loads reduced. At an average surface roughness (Ra) of 0.028 μm, the highest critical loads of TiN and TiAlN coating layers were 98 and 114 N, respectively. Tool performances of uncoated and coated tools were conducted under high speed machining (HSM) of AISI D2 cold-worked die steel (62 HRC). Consequently, the TiAlN coated end-mill using honing treatment showed excellent tool life under HSM conditions.
文摘Free abrasive particle machining in simple machine such as: honing, polishing can get higher surface finish mirror, but surface error, and working procedure is hard to control. Therefore, the vertical disposed ultra-precision plane honing method by ultra-particle diamond honing wheel is put forward to. The results of experiments indicate: plane-honing wheel has higher machining accuracy and machining efficiency. But at the same time the structure parameters of honing wheel effects on machining accuracy. By analyzing the relation of honing wheel structure parameters and workpiece machining accuracy, the relation of honing wheel and wear coefficient, then this paper gets honing wheel structure parameters in the condition of best accuracy coefficient and wear coefficient, and resolve the problem of choosing honing wheel structure parameters in ultra-precision plane honing at last. This paper analyses the relation of honing wheel structure parameters and workpiece machining accuracy coefficient and wear coefficient, by building relative movement math model of honing wheel and workpiece in plane honing. Through theory calculating, the result indicate: about honing machine tools for large volume manufacture, honing wheel wear is main effect factor, so honing wheel should adopt obverse triangle radial structure. About honing machining for high accuracy and low-batch quantities, machining accuracy coefficient is main factors; so honing wheel should adopt reverse triangle radial structure. Neglected the manufacturing factors of honing wheel, then we can design honing wheel with high power curve structure to meet the need of machining accuracy coefficient and honing wheel wear coefficient in higher accuracy honing.
文摘The removal mechanism is of importance to the grinding of hard and brittle ceramic materials. It is more suitable to analyze the material removal during ceramics honing processes by means of indention fracture approach. There are two honing characteristics different from grinding, the honing incidental tensile stresses and the crosshatch pattern. The stresses may influence material removal of brittle ceramics with lower tensile strength. In addition, the criss-cross cutting pattern on a bore known as crosshatch may also have its effect on the material removal of ceramics. The material removal of alumina is analyzed on the basis of honing characteristics, honing incidental tensile stresses and crosshatch pattern. By means of indentation fracture mechanics of brittle solids, the theoretical analysis of stress intensity factor and the crack response prove that honing incidental tensile stresses can increase the stress intensity factor of honing cracks and decrease the grinding stresses. So, the fracture criterion for crack propagation can be met easily. Therfore, it is possible to machine ceramic materials with small grinding forces in honing processes. The alumina honing experiments show that material at crosshatch intersecting point is removed by way of chipping which is similar to the edge-crumbled of ceramics. For brittle ceramics with lower tensile strength, such as Al 2O 3, SiO 2, the influences of the honing incidental tensile stresses and the crosshatch pattern on material removal are bigger than that of ceramics with relative higher toughness, such as ZrO 2 and Si 3N 4. Hence, the honing of Al 2O 3, SiO 2, is superior in cutting ability to the grinding. The large stock removal of brittle ceramic materials can be obtained through higher honing pressures. The increase in honing pressures can increase intensity factor of honing cracks, decrease the grinding stresses, and remarkably improve material removal rate. The researches show that honing is an efficient bore machining operation for brittle ceramics.
文摘In recent years, the new technology of ultrasonic vibration cutting has been drawing general attention. And great advancement in theory and applications in production of the technology have been achieved. Ultrasonic vibration honing system developed in North China Institute of Technology and Nanjing University of Aeronautics and Astronautics of cast iron cylinder (47×97) and thin cylinder of 20# (86×95) has been successfully applied to productive experiment and the technological effect obtained is ideal. In comparison with ordinary honing, ultrasonic vibration honing possesses apparent characteristics: Firstly, it has high processing precision (precision in size ranks IT6, roughness Ra0.05, circularty and cylindericity in size ranks IT6); Secondly, it has small cutting force and low temperature so that no deformation occurs; Thirdly, it has high efficiency. In this paper, the application of a new technique to honing is introduced, and the ultrasonic honing systems of thin cylinder and cast cylinder which have been successfully manufactured and their applying effect are illustrated. This paper analyzes the cutting principle of ultrasonic honing in terms of cutting motion, grain performance and cutting quantity. The study of this technique starts a new approach to which is efficient higher quality and lower consumption to hole’s precise and superprecise machining. At last,the paper introduce the conclution: Ultrasonic honing sharpens grain, which is favorable for raising cutting efficiency; Ultrasonic vibration honing may increase honing depth and raise cutting efficiency. It may also decrease honing power and system deformation; Undergoing practice we can find that the ultrasonic honing system as above discribed can be extended and applied to production. The system not only can be applied to conventional honing machine, its technology effect as good as high precision machine tool, but also can be applied to develop and study ultrasonic vibrating numbrical controlling honing machine tool which will provide a new type, efficient, high quality low consumption, equipment for working precision hole; Appling the same parament as W40 oilstone bar, under the same condition, is very valuable for product and application. Rough machining and finish machining once time finished, which not only improve location accuracy, but also have a high effiency.The honing system not only can be suitable for honing cast cylinder, but also can be applied for honing engineer ceramics as well as hard, crisp material; The dimension and technology paraments of 47 mm honing system as above discribed, can be suitable for honing the cast cylinder of motorcycle or minicar. And the cylinder diameter can be randomly selected from 45 to 65. The dimension and technology paramagnets of 86 honing system as above discribed,can be applied for honing all kinds of cylinder of light or heavy passenger-cargo vehicle, and the cylinder diameter can be randomly selected from 65 to 100; It is easy to achieve new technology of flat roof honing by applying ultrasonic honing.After the flat roof honing, fuel consumption of engine is 1g/Hp, while conventional engine is 3g/Hp.Life expectancy of engine is prolonged greatly after the cylinder by flat roof honing.
文摘In reality,it is easier and better to be honest.One of my favourite,and least favourite characteristics of my Chinese friends is that they are extremely honest.In the West,we spend a lot of time being extremely care-ful what we say to each other,and we also like to make sure that we are always
基金supported by The Natural Science Foundation of China(50975265)The Natural Science Foundation of Shanxi Province of China(2007011071)Program for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi(20080205ZX)
文摘ANIMAL husbandry technician Vasco Silva always found it difficult to master the technology applied to artificial insemination （AI） of cattle. However, in December last year. a training course changed the Mozambican＇s original thought of the technology and the way it is used,
