New development of pressure solder technology

Pressure solder (Pressure Welding) , solder in the process, must use force to weldment (heat or do not heat) , with finishing soldering method, main by resistance welding, friction welding, diffusion welding, ultrasonic solder, explosion solder, cold press the composition such as solder of solder, arc coming back and solder of magnetic force pulse. Solder of 0 foreword pressure is to solder one of important composition of science and technology, wide application is reached at aviation, spaceflight, the sources of energy, electron, car light industrial wait for a branch. Statistical data makes clear, solder with what pressure solder finishs quantity, occupy the world every year to always solder about the 1/3 of the quantity, have the tendency that continues to increase. Applied need is developed on industry to get used to new material, new technology, new product, in recent years, solder domestic and internationally in pressure solder contact forms theory, solder quality monitoring technology, solder the development of new technology and new facility and new material solder waited for a respect to make a large number of works. In view of pressure solder only appoint the meeting division of labor in Institute of Welding, the article makes one overview with respect to the new development of resistance welding and friction welding technology only. Resistance welding of new development of technology of 1 resistance welding (Resistance Welding) , pressure brings to bear on through electrode after workpiece is combined, the interface that uses electric current to pass contact and the resistor that adjacent area produces heat up the method that has soldering, main by spot welding, right the composition such as seam welding and solder, high frequency solder. Resistance welding is one kind solders quality is stable, manufacturing efficiency is tall, implement the join method of mechanization, automation easily. 1.

Head of 1 resistance welding forms theory to study head of progress resistance welding forms academic research to be resistance welding the development such as technology of monitoring of quality of new material, new technology, new facility, connect created a condition. Accordingly, it has taller academic theory sense not only, also have very big project economic value. 1. 1. Be pregnant with of solder frit nucleus treated domestic learned man at 1 o'clock the person such as Zhao Xi China, next is opposite is aided financially in national science foundation and American GM fund stuff of a variety of difficult solder metal (aluminium alloy, spring steel) began " theory of processing of be pregnant with of nucleus of spot welding frit and method " research, already obtained following positive result now: (1) the nucleus of spot welding frit that obtained all and caky organization to be brilliant waiting for an axis first (graph 1b) . (2) make be entirely first columnar the office of face of joint of nucleus of spot welding frit of brilliant appears area of brilliant waiting for an axis (graph 2b) . (3) enlarge the axial brilliant area such as frit nucleus, contractible frit nucleus is columnar brilliant area, curdle organizes grain to be refined significantly. (A) handle without be pregnant with (columnar brilliant + brilliant waiting for an axis) (B) handle through be pregnant with (brilliant waiting for an axis) pursue nucleus of frit of spot welding of 1 LY12CZ aluminium alloy (A) classics be pregnant with is handled (columnar brilliant organization and joint face) (B) handle through be pregnant with (joint, processing of be pregnant with can raise spot welding to receive a mechanical performance significantly, especially fatigue intensity. This is open up of technology of monitoring of spot welding quality a new way, from " qualitative " the respect improved quality of spot welding connect at all. 1. 1. The technology of imitate of numeric imitate numerical value of process of 2 resistance welding can is opposite neatly all sorts of influencing factor in resistance welding process undertake study, help people undertake a few research that pass a test impossibly and finish and analysis, consider to provide theoretic guidance for resistance welding thereby. The numeric imitate research that nods solder connect to fashion a process among them is the fundamental trend that this domain science studies to develop all the time. Current research basically is centered in behavior of the heat in spot welding process, report, force, namely the basic equation according to issue of heat of the description in physics, report, force, through the parameter in Cheng of the other side change and attrib border condition undertake hypothesis, build the mathematical model of spot welding process, be opposite with numeric method then field of the temperature field of spot welding process, electric current field, electromotive force field and stress, meet an emergency undertakes begging solving, mechanism of process of spot welding of research of in order to. The near future studies progress sees a table 1. Watch imitate of solder process numerical value considered to make progress at 1 o'clock 1. 1. Research of weldability of data of 3 new-style industry is new-style industrial data, a large number of application were won galvanization armor plate and aluminium alloy in auto industry, but the characteristic that goes up as a result of its physics function, weldability of its spot welding is very poor, especially of the electrode in spot welding process wear away and flyblow, affected stitch welding badly to produce. And small solder is nodded and stick the blemish such as solder to make spot welding receives a mechanical function and dependability to was not ensured again, especially aluminium alloy is more serious. Accordingly, must make the research with further careful development to the spot welding weldability of these material. Weldability of galvanization armor plate considers to basically center in the following respect: (1) law of film besmear compound (Zn of electric galvanization, galvanizing, hot plating, Fe alloy) reach film ply to affect. (2) affect each other between film and electrode head, french scholar T.

Dupuy damaged to electric extreme ministry special subject studies. (3) the mechanism of generation of configuration of frit nucleus crystallization, blemish, mechanical function relation with spot welding parameter. (4) mix to spot welding craft with new technology of information and control the process undertakes imitate is mixed forecast. Aluminium alloy board weldability research basically centers in the following respect: (1) electrode felt and splash generation mechanism and solve measure. For example, the small wave that splatters in aluminium alloy spot welding analyses research; In aluminium alloy board two sides parts plating is different the chromate layer of ply, the effect that changes osculatory resistor size considers to wait. (2) the numeric imitate of process of spot welding of aluminium alloy resistor and energy analysis. (3) design of technology of aluminium alloy spot welding and quality pilot intelligence change research. 1.

Quality of 2 resistance welding controls a technology to assure quality of resistance welding head, the core that raises its dependability is being produced namely advanced method and equipment are applied to carry out quality to control in the process. The extensive sex that uses as a result of spot welding craft especially, importance and have representative, technology of control of spot welding quality is the forward position that resistance welding domain studies and heat from beginning to end. Well-known, spot welding process is a height the nonlinear, process that action of much more variable coupling and many and random inaccuracy decide an element, have time of form nucleus process extremely short, be in close condition cannot observation, diagnostic signal extracts the oneself characteristic such as difficulty. This causes solder to nod quality parameter (frit nucleus diameter, intensity) cannot measure directly, can pass parameter of process of a few spot welding only (solder the voltage between electric current, electrode, dynamic resistor, energy, heat expands electrode displacement, sound blasts off, infra-red radiate and ultrasonic) undertake concluding secondhand, this is great the accuracy that affected monitoring of spot welding quality and dependability. Through longer exploration and practice, investigator already achieved following consensus: Developing much parameter to monitor a technology integratedly is the efficient way that raises precision of monitoring of spot welding quality, make full use of namely the information that monitor, use the reasonable method that build a model, build reasonable multivariate nonlinear the model that monitor makes this model can provide information of accurate, reliable spot welding quality inside wider condition, it is key of quality control technology. Consider to make clear, use nerve yuan technology of network theory, ambiguous logistic theory, numeric imitate and expert system be expected to solve real spot welding quality to be controlled directly, the research that dominates spot welding quality the technology is pushed to a new height. 1. 2. The scholar of 1 Germany of judge of grade of spot welding quality that is based on ambiguous classification theory Burmeister thinks, process of resistor spot welding is process of a classification, it is to cannot use formula to come clear description. A few maximum that pass parameter of process of monitoring point solder only or the least value will have one-sided description, the classification that can describe changeover to be a process from the function of the process so is described, build classified social estate with existing expert knowledge. Current, the method that useful already faintness classifies will evaluate solder the process signal that electric current causes (quantity of quantity of electrode displacement feature, electrode acceleration feature) the report that orders quality change with solder. The complexity that although apply to process of descriptive spot welding,points out ambiguous classification and nonlinear, can evaluate with the grade that nods quality at solder, but can give out only of parameter of solder drop quality roughly limits, and the effect that the accuracy of the evaluation avoids the ground to be an element by the numerous person such as expert knowledge hard. 1. 2. The multi-parameter of 2 spot welding quality that are based on regression to analyse theory monitor weldability of spot welding of methodological aluminium alloy poorer, apply increasingly extensive, urgent need solves problem of its quality monitoring. British scholar M.

The person such as HAO developed supervisory system of multi-parameter of spot welding of a kind of aluminium alloy, this system can collect spot welding process and the diagnostic amount that identify phenomenon of wider range process, the frit nucleus diameter that uses the methodological appraise that returns to an analysis to measure solder to nod and tensile strength, the experiment makes clear, the appraise that returns to a model measures a value to have enough accuracy. 1. 2. 3 be based on nerve yuan the much parameter of spot welding quality of network theory monitors the person such as allusion of domestic scholar Zhang Zhong integratedly to apply nerve yuan the network is academic, studied the model between resistor of mild steel trends and solder drop quality concerns, built spot welding mass model of ambiguous and integrated judge, the much parameter that realized quality of mild steel spot welding is monitored integratedly. The experiment makes clear, although be below abominable manufacturing condition, this system also monitors spot welding quality well and truly, determine reasonable quality order and degree, contented real time monitors the demand that after reaching solder, evaluates. 1. 2. The 4 frit nucleus diameters that are based on several estimation to calculate are online from scholar of adaptive control Japan on the west this method of the research and development waiting for a person with official opening needs to input the machinery that is pledged by weldment and its material and hot physics parameter beforehand before solder, when soldering at regular intervals interval detects solder the voltage between electric current and electrode, conduct mathematical model computation to give temperature field distributinging case according to heat, push those who calculate nucleus giving frit to grow in real time thereby circumstance, feedback accordingly control solders electric current rises with changing weld zone temperature slope. Through reasonable adjusting control each time Duan Wen spends ascendant slope, ensure frit nucleus achieves the diameter of the requirement before grown process and end. Actual production uses a proof, the settlement with this can better technology the spot welding quality of galvanization armor plate. Defect is this method needs to have a large number of online consideration, must use high-powered computer, make installation cost increases. Current, heat up with process of spot welding of aluminium alloy of imitate of numeric imitate method, report, mechanical process, the research that forecasts the growth of nucleus of spot welding frit, electrode to wear away to form a circumstance to wait with crackle is undertaking, gain certain headway. In the meantime, control faintness (FLC) and artificial nerve network (ANN) establishs modular photograph tie, system of excogitates control of spot welding intelligence is getting the attention of domestic and international scholar and enterprise. 1.

New technology of 3 resistance welding 1. 3. This craft can solve spot welding of heat treatment of temper of 1 random much pulse weldability is poorer but the contact brittleness that wait mixes hard steel of temper by dipping in water solder quality is not stable. Its craft characteristic is as follows: (1) use increscent electrode pressure (for identical board 1 when spot welding of thick mild steel.

5~1.

7 times) , modulation solders voltaic pulse (although increase by degrees with quantity of heat,control with reduce or avoiding inside splash) accept a macroscopical blemish in order to prevent spot welding (shrink loose, shrinkage cavity, crackle) generation. (2) use heat treatment of temper of random much pulse (≥ of N of temper pulse frequency 3) , in order to prevent defect of microstructure of spot welding connect (hard fragile martensite, burn a tissue too) appear, and organization of connect of accurate control spot welding reachs his to distributing feature, make area of contact tall stress obtains complete temper processing. According to the report, this craft compares the technology of double pulse spot welding that uses normally, can improve contact intensity and fatigue performance significantly. 1. 3. This craft can solve upset butt welding of 2 accurate pulse form dimension requirement is strict, the careful part that weldability difference and contact function have special demand is right solder. Its craft characteristic is as follows: (1) use modulation to solder pressure (come true through be the electromagnetism pressurization orgnaization of core by dc magnet) , make upset begins time and upset strength accurate, seasonable. (2) use pulse of modulation electric current (solder pulse + postheat handles pulse, heat treatment pulse can be odd pulse, double pulse and much pulse after) . (3) modulation solders pressure and pulse of modulation electric current can cooperate appropriately, comprise optimal and accurate pulse to solder to solder circularly, if pursue,3 are shown. Graph 3 TiNi remembers alloy nicety pulse to occupy a story to solder principle, this craft but better implementation remembers alloy (TiNi) , but hard alloy of temper by dipping in water and hot physics property differ pair of solder of bigger heterogeneous metal. 1. 3. Seam welding of resistor of heat conduction of seam welding of resistor of 3 heat conduction (Conductive Heat Resistance Seam Welding) it is to use welder of common and general resistance, pass the conduction with the hot resistor of iron, those who have aluminous capable person solder, have following advantages: Without hot crack blemish; With arc welding or method of other resistance welding photograph comparing has less in-house air hole; Solder high speed (seam welding of block of electrify of prep above general and arc welding, under laser beam welding) ; Medium equipment cost; Do not need fill metal or protect gas. 1.

New facility of 4 resistance welding is sub rectification resistor welder and inversion type the main way that resistance welding machine is development of welder of current world resistor; As contemporary control theory and electron yuan parts of an apparatus develops, its technology is crucial (low voltage big electric current brings difficulty to sub commutate; Pilot dependability and accuracy ask more advanced) solve basically already. Current, welder of inversion type resistor is the heat of preferential development. According to statistic, japanese Miyachi, Seiwa, european Messer, Tecna, the TJ Snow of North America, the Taesung of Korea, chinese Tianjin wait seven times to already had the product of this kinds of welder under capacity 300KVA. Graph 4 pursue for principle of welder of inversion type resistor. Graph machines and tools of resistance welding of type of inversion of sketch map of principle of welder of resistor of 4 inversion type has the following characteristic: (1) answer speed fast, control precision is tall. Because use taller inversion frequency (500~2000Hz) , time adjustment and feedback control cycle are in 1ms (1000Hz) less than, rose to solder greatly electric current controls precision. (2) volume is minor, weight is light. Because use the working frequency of intermediate frequency, solder when same power is outputted transformer bulk and weight are reduced apparently, according to the report, its weight can ease the grip of solder of type of an organic whole that uses inversion formula 50% . (3) three-phase load is balanced, power factor is high, energy-saving. (4) craft advantage is clear. Solder electric current is pulsatile dc (and ripple is spent small) , pass without communication 0 do not heat the defect of workpiece, quantity of heat can solder centrally all sorts of material. In the meantime, electrode life is obtained lengthen. Current, the main problem that confidential of inversion type resistance welding continues to study deep is: (1) of high-power switch component update ceaselessly. IGBT (ambipolar model segregation bar transistor) the component of first selection switch that is welder of resistor of type of development high-power inversion, its sheet is in charge of rated electric current to be able to amount to 300A, collect is shot extremely compression is as high as 1200V, can use logistic report to make the same score direct drive, realized the voltage control of component drive. (2) of high-power commutate diode update ceaselessly. As a result of sub commutate component accept the power loss that increased welder (occupy whole platform welder to output power about 28% ) , although use diode of Xiao Te radical to be able to get ameliorative, but the issue that still is put in output power to be added welder bulk and weight by system of limitation and its refrigeration. (3) main circuit develop attacks ceaseless development of the structure. Application solders at inversion the main circuit of power source has used simple structure of the following develop, push Zuo .

Circuit of the circuit of circuit of type inversion circuit, complete bridge-type inversion, half bridge-type inversion, odd inversion that carry type. Each inversion circuit has his actor drawback, want to the basis uses a condition actually and be decided. (4) inversion circuit is improved of control means ceaselessly. With why be being planted mode opens control means to improve main body to show to be in charge of in switch of the power in inversion circuit, namely hard switch and soft switch. In recent years, technology of soft switch of wide modulation of arteries and veins (SPWM) the research heat that becomes inversion to control a system, it is integrated technique of traditional wide modulation of arteries and veins is harmonious brace up technical advantage, change in power parts of an apparatus only shed the instant, apply syntonic principle, realize 0 voltage or changeover of 0 electric current, and method of wide modulation of constant frequency arteries and veins is used between time-sharing of the others greater part, finish the control that exports voltage or electricity to electric current, accordingly, the electricity that place of switch parts of an apparatus gets or voltage stress are little. Welder of inversion type resistor is particularly appropriate solder with nicety at the robot. In recent years, in the light of welder of sub commutate resistor and inversion type resistance welding machine all needs to soldering electric current undertakes sub commutate, a series of brings with respect to component of commutate of class of dimension of inevitable meeting existence issues, qing Dynasty of domestic scholar king is opposite on the foundation that development of welder of resistor of three-phase low frequency studies, developed without new technology of resistance welding of sub commutate dc, develop give to control the computer with industry (IPC) to control core, it is power switch component with IGBT, the inversion formula that uses section behead wave to control a method does not have prototype of welder of resistor of sub commutate dc, working principle sees a picture 5. The experiment makes clear, this machines and tools has good spot welding technical properties. Graph 5 inversion type does not have principle of road of Electromechanical of resistance welding of sub commutate dc to pursue 1.

Robot of 5 new-style spot welding nods solder robot to wait for composition by manipulator, controller and spot welding clamp normally, characteristic of robot of contemporary spot welding is: (1) use pincers of spot welding of type of inversion an organic whole, reduced a robot to catch greatly heavy. Have control precision tall, answer speed fast, energy-saving, solder technical properties is good wait for distinct advantage. (2) use new-style electrode actuating device. The clamp of servo type spot welding that appears in recent years (gun) , make positional feedback with servo motor, when the robot moves, the robot controls servo clamp to assist one of axes as its, can realize electrode pressurization soft contact and electrode pressure to adjust in real time, in with solder electric current is optimal after cooperating, raised spot welding significantly quality and eliminate splash. For example robot of spot welding of this kind of MOTOMAN already was in Japan, United States and Europe to win application. (3) change automatically quickly a variety of solder vice technologies. The robot contains solder clamp to store library, the diverse demand that can hold position according to solder or solder install the change of the product, automatic from store the library is caught change a clamp needing solder (graph 6) , those who increased a robot is flexible. (4) the quality that provides automation and crop control system, for example: The robot is three-dimensional laser vision system, the number is photographed resemble controlling a system, ray quality testing system, be helpful for soldering to the concentration of quality manages and be controlled. (5) leave a line new-styly to show teach a robot, but CAD/CAM of have the aid of gets weldment tectonic, solder the information such as condition and robot orgnaization, undertake be showinged from the line teaching, show teach time weak point, solder quality is stable. Graph 6 can change automatically the spot welding robot of solder clamp friction welding of new development of technology of 2 friction welding (Friction Welding) , it is to be below axial pressure and torque action, use solder the opposite motion between osculatory end panel and the attrition heat that plasticity flow place produces and plasticity are out of shape heat makes interface reachs his close area achieves voice of character sticking model to produce proper macroscopical plasticity to be out of shape, next rapid upset and finish a kind of when solder method that press solder, basically wait for composition by v of successive drive friction welding, inertial friction welding, agitate friction welding, linear friction welding, 3 body friction welding and attrition. The method of solid photograph join that friction welding is a kind of high grade, efficient, energy-saving, free from contamination. 2.

1 agitate friction welding (Friction Stir Welding, FSW) FSW is England solders institute (TWI) a patent technology that rolled out 1991, its principle sees a picture 7. Solder namely in the begining, on the agitate head that high speed rotates special form the juncture place that shows the club gets work, cause its and workpiece attrition heat build-up, make by solder the metal becomes plasticity state and agitate metal forms to rotate cavity, rotate cavity moves headlong along with attrition, the plasticity metal that is pushed to go out fills the cavity that forms before, refrigeration hind forms compact welding line namely. In whole solder in the process, the generation of cavity and cram undertake continuously, experience wears metal of welding line area to be out of shape by heat build-up of extruding, attrition, plasticity, move, diffuse and recrystallization. (Principle of A) agitate friction welding (on B) agitate head special form point to a club (C) solders the spot pursues 7 agitate friction welding (FSW) the advantage of agitate friction welding: (1) can solder plank reachs a variety of contact forms (butt joint, horn is received, build receive and T form connect) , can have different place (flat position welding, vertical position welding, admire solder and Fu solder to wait) solder. (2) can use at soldering fusion welding from time to tome the material of certain difficulty, if alloy of aluminium alloy, titanium reachs copper of cupreous aluminium, steel aluminium, steel, heat,originally the gender is plastic / thermoplastic plastic wait for heterogeneous material. In the meantime, also can solder ply is metabolic data, multilayer material. Forging to make material with casting between solder etc. (3) welding line quality is high, the limitation such as hot crack, stoma does not produce in contact, contact is mechanical performance is superior. For example, with argon arc solder photograph comparing solders aluminium alloy of series of × of 2 × × , its connect intensity raises 15%~20% , outspread rate rises 100% , fracture toughness rises 30% . In the meantime, solder be out of shape small, long even welding line is out of shape not big also, leftover stress is very low. (4) solder cost is low. Demand of the preparation before solder is low, allow juncture to have thin oxidation film and adherent foreign matter; Do not need solder aftertreatment; Need not stuff stuff and protective gas; (5) solder the process is not had fused, without splatter, smokeless dirt, low noise, it is one environmental protection model energy-saving join technology. The defect of agitate friction welding basically is, the weldment when applying solder needs rigid fastening, need mat having a back, welding line rear has spoon aperture to wait, these making that the technology of FSW is flexible be restricted. Have a lot of and distinct advantage in view of FSW, the development progress of this technology and its project application is very rapid in recent years, edison of British TWI, United States solders institute (EWI) , the institute of Beijing aviation craft of company of ESAB of German Stuttgart university, Sweden, China all made a large number of works, basically center in: (1) build FSW model. For example, the H of British Cambridge university.

R.

The Z of EWI of Shercliff, United States.

Feng developed what FSW of a kind of imitate heats up a process to heat model, use this model to be able to be calculated well and truly quickly a welder art parameter, understand this technology better heat and joint mechanism; The person such as domestic scholar Wang Jianhua put forward to be based on three-dimensional heat to play plasticity finite of yuan of analysis conduct heat and mechanical computation model, use this model to be able to understand field of the temperature in FSW process, the leftover stress after forecasting solder first and be out of shape. (2) appearance of change agitate head and material are qualitative, in order to get used to the need that different material solders. (3) the FSW technology that develops complex connect form, through rotating workpiece, use robot of numerical control type in order to be used at cricoid welding line, nonlinear welding line and three-dimensional welding line. (4) develop light qualitative magnesium alloy, and of magnesium alloy and aluminium alloy solder technology, develop the application in automobile industry. Agitate attrition spot welding (Friction Stir Spot Welding, FSSW) it is the specific form in FSW, undertake in the light of the join of automobile body of car aluminous structure developing study. FSSW device installation is on robot arm, when applying solder, by the robot the arm moves to want solder place, clamp arm drops place critical solder board, next agitate head drops undertake soldering, solder loosen after the end clamp arm, whole apparatus moves by robot arm new spot welding position, if the graph is shown 8 times,working process and finished solder are nodded. Graph spot welding of 8 agitate attrition (FSSW) (left) FSSW device (on) FSSW solder nods the exterior (below) dot of solder of FSSW of cross section of FSSW solder dot has one end length to spend L actually (L= π D2/d+2.

5mm, d is diameter of dot of the solder when spot welding of this plank resistor, d is special form diameter pointing to a club) , the experiment makes clear, the face of FSSW solder feature of AA6061-T4 plank is smooth, interior is flawless, the Jing Zaihe with have better is dynamic intensity. 2.

2 linear friction welding (Linear Friction Welding, LFW) LFW solders the process shows 9 times like the graph: Chafe pair of medium a side workpiece be worn by drive of a pair of reciprocator be made by the workpiece surface of clamp at another side relatively opposite motion, apply force to fall in its axial, undertake as what attrition moves, attrition surface is cleared and generation attrition is heated up, the metal of attrition surface amounts to voice of character sticking model to arise gradually be out of shape, form flash. Next, stop reciprocate and bring to bear on upset force, finish solder. Graph the advantage of friction welding of linear of sketch map of 9 linear friction welding: (1) can solder the metal with quadrate, circle, sectional polygon or plastic workpiece. Cooperate appropriate labour clamping apparatus to still can solder more irregular component, be like blade and eddy turntable solder (graph 10) . (2) solid state solders, the metal does not fuse and hot influence area is narrow; Low stress and small be out of shape, tall integrality; The structural intensity of welding line and stretch function and base metal are identical. Welder of the 11 LinFricTM of integral Xie Pantu that graph 10 LFW solders linear attrition (3) solder process but complete machine and automata, reliability is high (graph 11) . Accordingly, can realize many to solder, yi Ke is used on product line. Current, already soldered with LFW stainless steel, aluminous, titanium and nickel alloy, even the compound between the metal (, TiAl) and heterogeneous metal. Cambridge solders the institute has used LFW technology to make integral vane wheel in research, realize aviation engine hub and the whole that start airframe to solder. Northwest industry university began integral part of a historical period dish LFW solders the imitate of computer numerical value of field of the temperature in the process, stress field and solder of the process draft the job such as solid analysis and experiment of test and verify. CNC Milling