Field of temperature of laser reproducing bath detects research

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Summary: Reproducing technology is in laser to be paid close attention to generally domestic and internationally in recent years, form laser beam machining and advanced production technology a forward position and heat, already applied in the industry with get domestic and internationally essential. But a lot of among them fundamental theory problems still need to begin research deep, if the temperature in laser reproducing process reachs dimension precision control to detect,wait for a problem, make the application of laser reproducing technology got very big limitation. The article the principle with respect to laser reproducing, solution of temperature field analysis and detect the method made the introduction, summed up existing state of affairs of domestic and international development. Keyword: Laser reproducing; Temperature field; Bath; CCD. 1, foreword 80 time formed 20 centuries this starts reproducing project anew research domain, reproducing industry also arises subsequently. It is to use original part to use project of new and high surface (coating and modified) reach other processing technique, make the spare parts rehabilitates dimension, appearance and property, restore its to use value afresh, be equal to the service life that prolonged equipment actually, reduced the demand to primitive resource, saved resource. Laser reproducing technology already was paid close attention to generally in recent years in the world, form laser beam machining and advanced production technology a forward position and heat. The United States, England, France, Japan throws material resources of much labor power to begin research. College of our country part also began research in succession. 2, reproducing of laser of laser reproducing technology is the rehabilitate that the method that uses laser frit Fu realizes pair of metal component [1, 2] . Wait for technical powerful nation to take its seriously very from the United States since 1976, England, Japan, Germany, threw quite considerable labor power, material resources, financial capacity to have research, development, make the development of technology of laser frit Fu is accelerated apparently, in theory of laser frit Fu, physical maths model, parameter of alloy material, craft, coating organizes function research, equipment automation, flexible change, the respect such as monitoring of frit Fu process and manufacturing application obtained significant progress. If plan institute shows: The axis of Z of machine tool of numerical control of CNC of CO2 laser classics that laser gives out (perpendicular workbench) after illuminator, enter focusing of figuration of beam of light to combine lens, reentrance coaxial sends pink working head, assorted lens and working head are installed go up in axis of machine tool Z, consolidate control by numerical control system. Powder feeder of carrier gas type carries powder minute of pink implement, even ground sends head of coaxial job sending pink powder. Wait for repair spare parts to be located in on plane of X-Y of numerical control workbench, according to numerical control instruction, lens of workbench, combination is pressed with head sending pink given CAD/CAM software program moves, at the same time laser and powder are joined, laser coaxial sends pink working head " metallic pen " same, chase layer frit Fu. Detecting and control systematic action to fall, make the spare parts restores original measure. 3, the heat that research of field of temperature of reproducing of laser of imitate of field of temperature of laser beam machining is people attention all the time. The numeric analysis of field of temperature of laser frit Fu, distributinging character, numeric imitate, real time detects waited to the abecedarian studies [3] . Article general from analytic with numerical value two kinds of methods undertake an analysis to bath temperature field. Analytic solution is a foundation with counting credit analyse, get using function form denotive solution. In the whole process that seek solution, physical concept and logistic inference are clear, receives solution can be clear that the earth's surface shows an all sorts of elements to conduct the influence that process or temperature distributing to heat quite. The laser heat that uses three-dimensional and analytic computation to go out is conducted solder the computation with temperature field relatively accurate already model goes out to solder certainly the solder juncture below the standard combines dimension line, the power of heat source of the medium in receiving temperature field with laser beam welding of chronometer cipher out distributings and the temperature field of the infinity sheet that causes by this heat source distributings [4] . The laser blame frit that uses computation of half analytic method to give random to give beam of light to distributing coagulates field of temperature of heat treatment transient state and include change the laser that reachs the surface to absorb coefficient to change along with temperature and metallic stuff heat up action each other. But analytic solution goes against consideration border condition and photograph to change latent heat and parameter of sex of stuff hot other people follow the element such as temperature change to be opposite the influence of temperature field, the investigator when employing analytic solution so people often assume laser energy distributings for gauss, the content sex parameter of material is constant, take no account of photograph heated and radiate to come loose the element such as heat, this affected the accuracy that seeks solution on certain level. As the ceaseless progress of computer technology and development, this one powerful tool is opposite have the aid of the analytic method of temperature field had further research. If computer of have the aid of uses laser of YAG of analytic method computation,coagulate to frit of Ni3Al of the compound between the metal rule of change of field of temperature of stable state of the blame when processing [5] . The diversity of the complexity of laser beam machining and influencing factor, make temperature field model conducts next mensurable consistent maintenance in heat, but as a result of what differ severally " the history " condition and " environment " condition, make imitate result has very big difference. Investigator people to field of temperature of laser beam machining the processing way of each influencing factor is endless and same, all sorts of research have its reasonable one side as a result, the temperature field that specific requirement leaves avery kind of answer specific issue is specific analysis. Below the complex condition that decide solution, beg a laser very hard to heat the analytic solution of temperature field, so researcher seeks another kind of commonly used analysis means again, seek the numeric solution that sees temperature field with the numeric solution such as finite yuan of law, finite calculus of finite differences and numeric integration method. Numeric solution is a foundation with discrete mathematics, it is a tool with the computer, although its theory foundation is not as close in that way as analytic solution, but have very big adaptability to real problem. General a bit complex heat conducts a problem, can pass numeric solution to seek solution almost. Commonly used numeric solution has finite calculus of finite differences and finite yuan of law. Be in early the 20 gauss laser heat source that used the finite method that need branch to study movement about personnel before New Year more are three-dimensional heat conducts a model. Use numeric method to build flow of bath of Fu of frit of laser of 2 dimension quasi-steady state to reach conduct heat of the numeric model of the process build [6] , to the imitate of figure of free face of laser frit Fu, change to temperature field, photograph the organization distributings, the numeric imitate of material function. As the wide application of computer software technology, the numeric imitate of temperature field also got further research. Be like three-dimensional the computer computation imitate that sheds field temperature field, the field of temperature of spare parts of thin wall of three-dimensional transient state that built process of as fast as laser figuration to agree is calculated model. In addition the numeric solution of model of maths of field of temperature of research of method of useful still other is like law of network of nerve of small commutation law to wait. 4, temperature field detects technical temperature measures the measurement with the parameter such as length, quality, pressure to differ somewhat, it is the physics that uses certain material if function is linear expansion rate, resistor rate, electromotive force rate, thermal noise, hot (smooth) the radiation relation with temperature, of the sensor of temperature of of feeling lukewarm parts of an apparatus with sundry make it, the metabolic quantity that follows temperature through them obtains temperature to be worth secondhand. Temperature is according to thermodynamic the 0th law measures, with the temperature that is in the sensor in balancing state system to have identical temperature to be considered as the system that be measured. But because heat up those who balance voice to build very god-given, some circumstances fall and impossible, the accuracy that measures because of this temperature assures hard normally or say that he cannot ask quite too tall, it is more difficult to should measure transient state temperature. Commonly used measure lukewarm general component to measure law and blame contact to measure a way for contact two kinds big [7] . The ability when the contact measures lukewarm great majority to wait to heat up a balance determines correctly temperature, measure the process can suffer character of the object that be measured to reach conduct heat the influence of means, make what determine temperature and actual temperature cannot be consistent. Have when medium caustic, the term of service that measures component below high temperature condition shortens relatively, accuracy also can be reduced accordingly. The contact measures lukewarm appearance to basically have expand type thermometer, resistor thermometer, pyroelectricity thermometer, other contacts a thermometer, wait like acoustics thermometer, thermal noise thermometer, crystal thermometer, fiber-optic thermometer, these application are less. Blame contact is measured lukewarm it is a basis mostly the heat radiation of the object that be measured, according to its brightness or the volume that radiant energy measures, indirect and computative the temperature of the object that be measured. Basically have brightness thermometer, radiation thermometer, colorimetric thermometer. In laser reproducing process, the hot process of laser bath is perforative and whole machine a process, all physico-chemical processes are happen in hot process and develop, because the measure of the high-energy density of laser and focusing is small,wait for a characteristic, this one process is finish inside cutty time, make the bath temperature field of laser reproducing detects become more difficult, laser temperature field detects belong to high temperature to measure, current research basically is built go up in the numeric analysis to bath temperature field. Be like: Choose the infra-red specific value that has property of tall interference rejection to measure lukewarm method, use sheet piece machine undertake data processing, provide the protective refrigeration unit that measures lukewarm control switch and sensor automatically, those who realized fuse-element temperature is online detect; Online and infra-red trichromatic the research that radiation measures lukewarm new technology and applied technology; The development that infra-red colorimetric measures Wen Yi [8] . Above is the academic research that is based on numeric analysis, joined CCD camera to will measure lukewarm method to be improved further again later, the real time that can get temperature field films picture, benefit handles a technology to consider to do farther test and verify to detecting theoretically with computer image. 5, the rehabilitate that conclusion reproducing promotes gradually as a kind of advanced production technology or replaces a tradition maintains a measure, laser reproducing technology also received wide application, bath temperature field detects an all in all technology segment is in laser reproducing technology, it laid a foundation for technology design and precision control. The article is reached to the analytic method of temperature field detect the technology was done elaborate in detail. As the ceaseless development of computer technology, especially the wide application of image processing technology, of field of laser bath temperature detect the technology will change directional development to visible, intelligence. CNC Milling CNC Machining