The technology that laser beam welding receives and technology

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One, the craft parameter that laser beam welding receives. 1, power density. Power density is one of the most crucial parameter in laser beam machining. Use higher power density, inside limits of small second time, surface layer can heat to boiling point, produce a large number of vaporization. Accordingly, high power density is machined to material purify, if stiletto, cut, sculpture is advantageous. To inferior power density, surface layer temperature achieves boiling point to need to experience several millisecond, before surface layer vaporization, ground floor reachs melting point, easy form good melt to solder. Accordingly, in conduct model laser beam welding is received in, power density is in in limits 104~106W/cm2. 2, laser pulse is undee. Laser pulse weaveform solders in laser in it is a serious problem, it is more important to solder to chip especially. Stimulate beam of light to shoot when high strenth to material surface, the laser energy that metallic surface will have 60~98% is reflexed and the loss is dropped, and reflectivity changes along with exterior temperature. During action of pulse of a laser inside, the change of metallic reflectivity is very big. 3, laser pulse width. Arteries and veins is wide it is one of important parameter that pulse laser solders, its since distinguishs the important parameter that fuses at material purify and material, also be the crucial parameter that decides to process facility cost and volume. 4, leave anxious quantity right to solder the influence of quality. Laser solders to need to leave make an issue of certainly normally one, the power density that manages facula center because of laser focus is exorbitant, evaporate easily aperture. On each plane that leaves laser central issue, power density distributings relatively even. Have two kinds from anxious means: Leaving anxious with negative from anxious. Anxious plane is located in workpiece upper part to be leaving anxious, leave to lose conversely anxious. Press geometrical optics theory, should losing from make an issue of one equal when, density of the power on place correspondence plane is approximate and identical, but the bath figure that wins actually is different. Lose from Jiao Shi, can obtain bigger frit deep, the formation of this and bath the process is concerned. The experiment makes clear, laser heats 50~200us material begins to fuse, form fluid photograph metal and appear vaporization asking cent, form city to press vapour, and with extremely tall speed eject, give out dazzling Bai Guang. Meanwhile, system of high concentration steam makes campaign of fluid photograph metal comes bath brim, form in bath center cave. Should lose from Jiao Shi, density of material interior power is higher than the surface, easy form stronger fused, vaporization, make light energy to material more in deliver. In applying actually so, should ask frit is deep bigger when, use negative from anxious; Solder when weak data, appropriate is used leaving anxious. 2, laser beam welding receives technique: 1, piece with piece between solder. Include to penetrate to solder, upright solder, center fused solder, center punchs 4 kinds of technique such as fused solder. 2, of silk and silk solder. Include silk and silk to be built to solder, across solder, parallel receive 4 kinds of technique such as solder, T solder. 3, of tinsel and lump component solder. Use laser beam welding to accept the connection of OK and successful implementation tinsel and lump component, the dimension of lump component is OK and aleatoric. The geometrical size of filiform component should note in solder. 4, of different metal solder. Solder not to want to solve with the metal of the type solderability and but solder parameter limits. The laser between different material solders to only certain and specific data combines gift likely. The link that solder of laser drill rod has some of element is unfavorable use laser fusion welding, but can use laser to serve as heat source, apply solder of soft drill rod and solder of hard drill steel, have the advantage of laser fusion welding likewise. The means that uses drill rod solder has a variety of, among them, solder of laser soft drill rod basically is used at printed circuit board solder, use at actually especially piece shape component assembles a technology. 3, adopt solder of laser soft drill rod and other means posture than having the following advantage: 1, because be local heating, component produces fire damage not easily, hot influence area is small, because this can be in,solder of soft drill rod applies near heat quick component. 2, heat with blame contact, fused bandwidth, do not need any auxiliary tools, the treatment after double-faced component equips on circuit board can be brushed in perfecting. 3, it is good to repeat operation stability. Welding flux has pollution to welder small, and laser irradiation time and output power are controlled easily, n of solder of laser drill rod is tall. 4, stimulate beam of light to come true easily prismatic, can wait for optical component to undertake time is broken up with the space with lens of half lens, illuminator, prism, scanning, can achieve much point at the same time symmetrical solder. 5, solder of laser drill rod is multi-purpose wavelengh 1.

The laser of 06um serves as heat source, fine transmits usable light, because this can be in,the place that groovy means solders not easily undertakes machining, flexibility is good. 6, focusing sex is good, realize multitask easily the automation of device. 4, laser deep fusion welding: 1, metallurgy process and craft theory. Process of physics of metallurgy of laser deep fusion welding and electron beam solder are very similar, namely energy changeover mechanism is to pass " alveolus " the structure will finish. Be in enough below illuminate of tall power density beam of light, material generation evaporates form alveolus. This is full of steam alveolus to be just as a boldface, draw the energy of incident light entirely almost, temperature of the balance inside aperture antrum amounts to 25000 degrees or so. Quantity of heat is delivered from the wall outside antrum of aperture of this high temperature come out, make the metal that surrounding this aperture antrum fused. Be full of inside alveolus evaporate continuously in material of body of the wall below illuminate of beam of light the high temperature vapour of generation, 4 walls are surrounding alveolus melt metal, liquid state metal all around namely round solid material. The steam that the liquid outside hole wall flows and produces continuously inside tension of mural layer surface and aperture antrum presses force be locked in a stalemate and maintaining dynamic balance. Beam of light enters alveolus ceaselessly, the material outside alveolus is flowing continuously, move as beam of light, alveolus is in stable condition of flow from beginning to end. That is to say, alveolus and the melt metal round hole wall advance as bellwether beam of light rate moves ahead, melt metal stuff is worn the gap that after alveolus removeds, leaves and subsequently condensation, welding line is formed then. 2, influencing factor. Deep to laser fusion welding produces the element of the influence to include: Laser power, stimulate diameter of beam of light, material absorptivity, solder speed, protect gas, lens is anxious long, focal position, dash seat of beam of light, solder initiative rise gradually with the laser power that ends a point, fall gradually control. 3, the feature of laser deep fusion welding: Feature: (1) tall deep wide than. Because of melt metal round cylindrical housing of high temperature vapour is formed and outspread to workpiece, welding line becomes deep and narrow. (2) the smallest hot input. Because source antrum temperature is very high, fused process occurs lickety-split, input workpiece quantity of heat is extremely low, heat is out of shape and hot influence area is very small. (3) tall compact sex. Because be full of alveolus of high temperature steam to be helpful for frit receiving bath agitate and aeriform transgression, bring about generate solder fully without stomatic frit. The high cooling rate after solder makes welding line organization is changed imperceptibly easily again. (4) strong welding line. (5) accurate control. (6) blame contact, big gas welding receives a process. 4, the advantage of laser deep fusion welding: (1) because focusing stimulates beam of light to be had than groovy method,get much power density high, bring about solder rate is rapid, hot influence area and be out of shape lesser, still can solder the difficult solder material such as titanium, quartz. (2) be transmitted easily because of beam of light and control, do not need to often change again solder fire, nozzle, decrease significantly stop machine is auxiliary time, have coefficient of carry on one's shoulder and manufacturing efficiency so tall. (3) as a result of rarefied action and high cooling rate, welding line is strong, integral performance is high. (4) because the balance is hot the input is low, treatment precision is tall, can reduce rework cost. Additional, laser beam welding receives move turn fare is lower also, can reduce manufacturing cost. (5) implement automation easily, to beam of light intensity and careful fixed position can have effective control. 5, equipment of laser deep fusion welding: Laser deep fusion welding chooses laser of successive wave CO2 normally, this kind of laser can be maintained enough high output power, generation " alveolus " effect, frit is fully whole workpiece is sectional, form coriaceous to solder contact. With respect to laser itself character, it just can arise can serve as heat source, directional the device of good parallel beam of light. If direct it,mix after be being handled effectively, shoot to workpiece, its power input has strong consistence, those who make can be better get used to automation process. Solder to be carried out effectively, laser and a few otherer necessary optics, machinery and control unit comprise to solder greatly jointly together system. This system includes what laser, beam of light transmits package, workpiece to assemble and unassemble with mobile unit, still have control equipment. This system can be be carried simply by hand by handlers only and secure work, also can be to include work can automatic outfit, discharge, fixed, solder, examine. The design of this system and executive total demand are to be able to be obtained solder approvingly quality and tall manufacturing efficiency. 5, the laser of steely material solders: 1, the laser of carbolic steel and common alloy steel solders. Say always, carbolic steel laser beam welding receives the result good, its solder quality depends on matter content. Solder just like other technology is same, sulfur and phosphor are generation solders the sensitive element of crackle. Solder approvingly to obtain quality, carbolic content exceeds 0.

25% when need warm-up. Should differ when the steel of the quantity that contain carbon solders each other, solder fire but a bit deflection small material with carbon element at the same time, in order to ensure contact quality. Steel of low carbon boiling because the content of sulfur, phosphor is high, do not suit laser beam welding to receive. Low carbon is composed steel as a result of low matter content, solder the effect is very good. Medium, high-carbon steel and common alloy steel can undertake good laser solders, but need warm-up and solder aftertreatment, in order to eliminate stress, avoid crackle to form. 2, the laser of stainless steel solders. Below general situation, stainless steel laser solders than convention more win high grade contact easily. Because solder high,speed heat affects an area very small, sensitize does not become serious problem. Compare with carbolic steel photograph, the thermal conductivity coefficient with low stainless steel more obtain deep frit easily narrow welding line. 3, the laser between different metal solders. Laser beam welding receives extremely high cooling rate and very small hot influence area, solder for a lot of different metals the data phase look that there is different structure after melting created advantage. It is OK to already proved the following metal now success laser deep frit solders: Mild steel of stainless steel ~ , stainless steel of ~310 of 416 stainless steel, alloy of nickel of ~HASTALLY of 347 stainless steel, steel of cold forging of nickel electrode ~ , the bimetallic of different nickel content is taken. CNC Milling