Summary of the invention
The object of the present invention is to provide a kind of twin-laser that adopts to implement laser weld to aluminium alloyMethod, this method can change the surface microscopic topographic of aluminium alloy, aluminum alloy surface fusing is formed moltenPond, to promote the absorptivity of aluminium alloy to continuous-wave laser beam, improves welding quality.
The invention provides a kind of method that adopts twin-laser metal material to be implemented to laser weld, compriseFollowing steps:
Step 1: welding material is cleared up, and welding material is installed fixing;
Step 2: adopt twin-laser to produce two bundle laser, this two bundles Laser Focusing is in welding materialSurface;
Step 3: at the surface of welding material side-blown protective gas;
Step 4: beam of laser is occurred by quasi-continuous laser, forms welding material surface meltingMolten bath;
Step 5: the second bundle continuous laser beam focuses on the welding material region of having melted;
Step 6: this two bundles laser beam is with given sweep speed synchronizing moving, at the table of welding materialFace forms weld seam, completes welding.
The invention has the beneficial effects as follows, this method can change the surface microscopic topographic of aluminium alloy, makes aluminiumAlloy surface fusing forms molten bath, to promote the absorptivity of aluminium alloy to continuous-wave laser beam, improves welderingConnect quality.
Detailed description of the invention
Refer to shown in Fig. 1, the invention provides a kind of twin-laser that adopts metal material is implemented to laserThe method of welding, comprises the steps:
Step 1: welding material is cleared up with sand paper, and welding material is fixed on to weldingOn platform, ready.
Step 2: adopt twin-laser to produce two bundle laser, this two bundles Laser Focusing is in welding materialSurface, described twin-laser is respectively quasi-continuous laser and continuous wave laser, this quasi-continuous laserPeak power output is 100-500W, and pulse width is 50-200ns, and repetition rate is10kHz-30kHz, peak power is greater than 105W, described continuous wave laser peak power output is500-10000W, described welding material is aluminium alloy, copper alloy, fine aluminium or pure copper material;
Because aluminium alloy and copper alloy have higher reflectivity, close for Laser Welding of Aluminum Alloys, copperGold laser weld is difficult for forming molten bath, and solderability is poor. Quasi-continuous laser has higher peak power,Can reach 105W/cm2Above, under the laser beam condition with high-peak power, aluminium alloy and copper alloySurface easily forms molten bath, and liquid molten bath can increase the absorption of welding material to laser beam energyRate.
Although the laser beam that quasi-continuous laser produces has very high peak power, be limited to currentTechnical merit, the mean power of the type laser beam is no more than 1000W conventionally, only adopts quasi-continuous sharpLight device is implemented welding to aluminium alloy, copper alloy, and because mean power is low, the depth of weld is less. And connectAlthough the laser beam that continuous laser instrument produces can not reach larger peak power, can reach higherMean power, such as 10000W, even higher. Therefore, swash with continuous in conjunction with quasi-continuous laserThe two advantage of light device, adopts continuous wave laser to produce continuous laser beam while irradiation on welding material surfaceSame position, due to quasi-continuous lasing bundle can make welding material surface melting form molten bath, liquid stateWelding material laser beam is had to very high absorptivity, can be by continuous laser beam energy larger powerAmount absorbs welding material, forms darker weld seam, can realize higher welding efficiency, also canImprove the quality of welding.
Step 3: the surface of welding material side-blown protective gas, described side-blown protective gas, this guarantorProtecting gas is Ar gas, He gas or N gas, or the mixing of the arbitrary proportion of Ar gas, He gas and N gasGas;
Laser beam welding, more than welding material temperature raises rapidly and reaches boiling point, at welding materialTop, molten bath forms plasma, metal vapors etc., and especially plasma has certain to laser beamShielding action, reduces the laser energy that arrives molten bath, and airborne oxygen is easy in welding process in additionReact with welding material, welding material is oxidized. In laser beam welding, in weldingMaterial surface side-blown protective gas, can dispel plasma, and forms lazy on welding material surfaceProperty gas atmosphere, can effectively avoid the welding material oxidation of high temperature. The effect of side-blown gas determinesSide-blown gas must be inert gas, and be difficult for being ionized. Be generally Ar gas, He gas orN gas, or the mist of Ar gas, He gas, N gas arbitrary proportion.
Step 4: beam of laser is occurred by quasi-continuous laser, forms welding material surface meltingMolten bath, the pulse peak power of this beam of laser can reach 105W magnitude, can change the table of aluminium alloyFace microscopic appearance;
Quasi-continuous lasing is produced by quasi-continuous laser, and passes through optical fibre transmission to laser head, line focusAfter, the focus of quasi-continuous lasing bundle is acted on to the surface of welding material, due to quasi-continuous lasing bundle arteries and veinsRush width and only have 50-200nm, therefore can obtain very high peak power density, in the extremely short timeInside make welding material temperature reach fusing point, thereby form molten bath.
Step 5: the second bundle continuous laser beam focuses on the welding material region of having melted;
In current industrial continuous wave laser produce continuous laser beam, although do not have quasi-continuous laser thatHigh peak power, but its mean power is conventionally higher, and power output is commonly 500-10000W.In conjunction with quasi-continuous lasing bundle, can more give full play to the powerful advantage of continuous laser beam, aluminium is closedThe laser solderability of gold and copper alloy is improved, and welding quality improves.
In laser beam welding, the hot spot of first, second Shu Jiguang is between welding material surperficialDistance is 0-3mm; In the time that spacing is 0, the center superposition of two bundle laser beams; In the time that spacing is greater than 0,The laser beam of quasi-continuous laser is positioned at the front of welding direction, and the laser beam of continuous wave laser is positioned at welderingConnect the rear of direction, the sweep speed of described first, second Shu Jiguang is 5-60mm/s; Quasi-continuous sharpLight beam rear, is in order to make welding material first at quasi-continuous lasing Shu Zuoyong at front, continuous laser beamLower formation molten bath, then, under the effect of continuous laser beam, has larger to continuous laser beam energyAbsorptivity, the utilization rate of raising laser energy, improves aluminium alloy and copper alloy Laser Welding Quality.
Step 6: this two bundles laser beam is with given sweep speed synchronizing moving, at the table of welding materialFace forms weld seam, completes welding.
First, second laser is produced by quasi-continuous laser and continuous wave laser respectively, passes through respectively lightFine, laser head focuses on welding material surface, and two processing heads are fixed on same industrial robot or latheEnd, by adjusting two processing head spacing and relative angles, the laser beam of quasi-continuous laser outputBe positioned at the front of welding direction, the laser beam of continuous-wave laser output is positioned at the rear of welding direction.By computer control industrial robot or machine tool motion, make first, second laser synchronization motion, makeThe fusing of welding material experience, natural cooling process, form weld seam.
Form molten bath because quasi-continuous lasing bundle makes aluminum alloy surface, make aluminium alloy to continuous laserAbsorptivity significantly improves, and welding process is without welding wire. Weld seam pattern is good, no significant defect, and weld seam is anti-Tensile strength can reach the more than 90% of mother metal.
Above-described specific embodiment, carries out object of the present invention, technical scheme and beneficial effectFurther description, institute it should be understood that the foregoing is only specific embodiments of the invention and, be not limited to the present invention, within the spirit and principles in the present invention all, any repairing of doingProtection scope of the present invention changes, be equal to replacement, improvement etc., within all should be included in.