How utmost assures Laser Cutting quality

In the process of machine of use Laser Cutting, how does utmost assure Laser Cutting quality? Lai of benefit of method of China labour laser hints you, the main factor that power of output of pressure of the adjustment of position of cut speed, focus, auxiliary gas, laser and workpiece character is quality of Laser Cutting of a few big impacts. Besides, workpiece clamp device is crucial also to assuring cut quality, because be in Laser Cutting process, heat and stress are released pervade whole workpiece, it is this to must consider to use the fixed workpiece method that suits, move with avoiding to cause work, affect the accuracy of cut work measure. One, cut speed is right to the influence of cut quality given laser power density and material, cut speed is accorded with at an experience type, want to connecting threshold value above only, the cut speed of material and laser power density become direct ratio, increase power density to be able to raise cut rate namely. The power density that indicates here not only with laser output power is concerned, and concern with mode of quality of beam of light. Additional, the feature of system of focusing of beam of light, namely the facula size after focusing also has very big effect to Laser Cutting. Cut speed and by the density of cut material (specific gravity) become inverse ratio with ply. Keep changeless when other parameter, the element that raises cut rate is: Enhance power (inside certain limits, be like 500 ～ 2 000W) ; Improve mode of beam of light (if arrive from high-ranking model low rank model till TEM00) ; Reduce focusing facula size (if use focusing of lens of short focal distance) ; Cut is small initiative evaporate can material (wait like plastic, organic glass) ; Material of cut low density (wait like Bai Songmu) ; Cut thin profile expects. Particularly right metallic stuff, below the condition that keeps constant in other technology variable, laser Cutting speed can have a cut quality that still can keep relative to adjusting range more satisfactory, this kind of adjusting range appears when cut thin metal than thick a bit wide. Sometimes, cut speed slants to also be met slow bring about eduction to heat up surface of mouth of ablation of material of be in harmony, make tangent plane very coarse. 2, the influence that focal position adjusts pair of cut quality because laser power density is very big to cut speed influence, lens is anxious long choice is a serious problem. Stimulate volume of spot of gloriole of focusing of beam of light and direct ratio of lenticular Jiao Changcheng, classics of beam of light is short size of spot of gloriole of focusing of anxious long lens is very small, density of focal place power is very high, very advantageous to material cut; But its defect is Jiao Shen very short, tone surplus amount is small, apply to thin profile of high speed cut to expect quite commonly. Because grow anxious long lens to have wider Jiao Shen, want to have enough power density only, suit cut deep work quite. Using certainly why to plant anxious after long lens, the relative position of focus and workpiece surface is attached most importance to especially to assuring cut quality should. Because density of focal place power is highest, below most circumstance, position of the focus when cut just lay workpiece surface, or it is a little under the surface. In whole cut process, ensuring focus and work look are constant to the position is the fundamental condition that obtains stable cut quality. Sometimes, the because of cooling not to be pooh-poohed be heated in lenticular job causes anxious senior change thereby, this adjusts focal position in time with respect to need. When the focus is in optimal position, kerf the smallest, efficiency is highest, optimal cut speed can achieve optimal cut result. In great majority application the circumstance falls, focus of beam of light is adjusted just was in nozzle to fall. Nozzle and workpiece surface span are commonly 1.

5mm left and right sides. 3, the influence of auxiliary gas pressure to cut quality usually, material cut needs to use auxiliary gas, main drag in reachs the issue the type of auxiliary gas and pressure. Normally, auxiliary gas and stimulate coaxial of beam of light ejective, protective lens is avoided get pollution and play cut area root slaggy. To metalloid material and partial metal stuff, use compress air or inert gase, keep clear of to melt and evaporate material, control cut area at the same time excessive combustion. Use active gas to most metal Laser Cutting (as long as it is O2) , form produce oxidation exothermic reaction with blazing metal, add quantity of heat can increase this share 1/2 of ～ of cut speed 1/3. In ensure auxiliary gas premise falls, aeriform pressure size is a very main factor. When thin profile of high speed cut expects, the aeriform pressure with higher need sticks broken bits with preventing cut the reverse side (heat sticks broken bits to workpiece to return meeting injury to cut a margin) . Increase when material ply or when cut rate is slower criterion aeriform pressure appropriate is reduced appropriately, to prevent plastic cut Bian Shuang to change, also with cut of inferior gas pressure had better. Laser Cutting practice makes clear, when auxiliary gas is O2, its purity has apparent effect to cut quality. O2 purity reduces 2% meetings to lower the cut rate of 50% , bring about cut quality to become poor significantly. For the laser that the influence of power of output of nextpage4, laser to cut quality outputs to successive wave, power volume and mode stand or fall meet laser to produce main effect to cut. When be being operated actually, often install most high-power in order to achieve higher cut rate, or cut of in order to is deeper material. But mode of beam of light (energy of beam of light on cross section distributing) appear more important sometimes, and, when enhancing output power, mode often has a bit subsequently become poor. Changke discovers, in be less than most place of the focus below high-power state obtains supreme power density however, acquire optimal cut quality. In laser during life of whole and effective job, mode is abhorrent. The change with slight gas mixture of job of the state of optical component, laser and flow fluctuation, can affect mode orgnaization. The place on put together is narrated, although the element of influence Laser Cutting is relatively complex, but pressure of position of cut speed, focus, auxiliary gas and laser power and mode structure are 4 the most important variable. In cut process, if discover cut quality becomes poor apparently, the ingredient that should examine above discussion above all tries in time adjusting control. 5, workpiece character is right to the influence of cut quality Laser Cutting quality even whether cut impact is the biggest be like next elements: 1.

Material surface reflectivity blasts off to CO2 laser 10 what go out.

For the beam of light outside 6mm Yuan Gong, it is better that metalloid material is absorbed to it, have tall absorptivity namely, face metal stuff is right 10.

6mm beam of light is absorbed poorer, the gold that has tall reflectivity especially, silver-colored, copper and aluminous metal, general to this kind of material unsuited stimulate beam of light with CO2, especially successive wave beam of light comes cut. To metal of aluminous, copper character, want to form enough initiative power to need 3kW above commonly, in order to obtain the initiative alveolus that penetrable effect place needs. Black metal is steely material and kind of nickel, titanium to 10.

The CO2 beam of light of 6mm has certain absorptivity, heat when material surface especially after constant temperature or oxidation film, its absorptivity still can rise substantially, achieve better cut result thereby. To opaque material, absorptivity ＝ (1 - reflectivity) , concern with material surface condition, temperature and wavelengh. Material is heating to the absorptivity size of beam of light initial phase has main effect, but once work is in-house,alveolus is formed, the boldface effect of alveolus makes material adjacent to the absorptivity of beam of light 100% . 2.

The exterior condition of material of material surface condition affects the absorption to beam of light directly, especially exterior surface roughness and the apparent change that exterior oxidation layer can cause exterior absorptivity. In Laser Cutting practice, can use material surface condition to improve the cut performance of material to the influence of absorptivity of beam of light sometimes. 6, the other factor influence to cut quality 1.

Design and make quality of good to obtaining cut what affect cutting torch of cutting torch and nozzle producing main effect, especially nozzle. If nozzle is chosen undeserved or safeguard not to be pooh-poohed easy cause pollution or injure, or the circularity as a result of nozzle mouth bad or cause because of heating up a metal to splatter local jam, can form eddy current in nozzle, bring about cut function to become poor apparently. Sometimes, nozzle mouth and focusing beam of light are not coaxial, form beam of light to cut nozzle margin, also can affect the quality that cut a margin, increase cut seam width and make cut dimension amlposition. To nozzle, want special attention two problems. (1) the influence of nozzle diameter. Nozzle mouth size has certain effect to cut speed, nozzle mouth size also affects exit pressure to distributing. Nozzle diameter increases, because jet sheds the strong cooling action of capable person of pair of cut area mother,make heat affects area narrow, but also can bring about cut had seamed wide, and nozzle size can cause collimation difficulty, nozzle mouth has the risk of the cut that be cut by beam of light, and, cut had seamed narrow, the successful eduction with meeting slaggy block up falls in high cut rate. (2) the influence of nozzle and workpiece surface span. Nozzle and workpiece span affect nozzle air current and workpiece to cut seamed coupling directly. Nozzle mouth too near workpiece surface, to lens meeting generation returns pressure strongly, abate produce what material nods to break up to spray cut ability, have adverse effect to cut quality, but the distance can cause needless kinetic energy loss again too far, adverse also to significant cut. General, spout and workpiece span control are in 1 ～ 2mm is advisable, the cutting torch of system of contemporary Laser Cutting deserves to have inductance or unit of feedback of capacitance type sensor, be in with self-adjusting both distance beforehand inside the high limits of set. 2.

Outside the transmission that the primitive beam of light that the influence laser of smooth route system shoots is system of route of the light outside the course (include reflection and transmission) , with extremely high power density well and truly illuminate arrives the surface of workpiece. Outside the optical component of smooth route system should be adjusted regular examination, in time, when ensuring when cut fire moves in workpiece upper part, beam of light transmits lenticular center correctly and focusing becomes very small spot, have high quality cut to workpiece. Once positions of any one optical component produce change or be polluted among them, can affect cut quality, cause cut to cannot undertake even. Smooth road lens is splattered outside by pollution of the impurity in air current and cut area particle felt, or lens refrigeration is insufficient, can make lens produces overheat, energy of influence beam of light is transmitted. Cause smooth road to collimation spends drift and cause serious consequence, lenticular overheat still can produce a central issue lack fidelity, endanger lenticular itself even. Once optical component is stuck even by pollution go up cut child small particle, clearing to it is very important and the issue that often can be ignored, list below a few clean a point: (1) of lens clean: Brush camera lens paper to be bent a few fold, with a few analysises pure acetone is soaked; Wipe camera lens surface gently with soaked camera lens paper, the attention cannot press lens with finger; Relapse a few times, till lens surface cleanness, stay in lens face without bilge and remaining trace; Blow with dry air dry; Can become the camera lens scroll that wets with a few acetone when necessary lever, swab lens surface gently, weigh with purify corrupt drop. Those who want an attention is acetone easy absorb itself of humidity and moisture pollution acetone from inside air, want to build close acetone bottle so, in must not returning the acetone fluid that after cleaning, remains new acetone bottle. (2) of illuminator lens clean: Remove lens from lens wearing; On lens look out, put camera lens paper on lens face; Drip on camera lens paper a few acetone, pull hold up of camera lens paper gently to cross lens face; Relapse afore-mentioned working procedure, till lens face is clean, stay in lens face without defilement and incomplete be soiled; Load lens again lens. If use molybdenum lens to make illuminator, because of it cannot film, polishing hind can be used directly, so it can use water (suds or the water that contain the seed that wash clean) wash lens face. But the lens that other surface has film cannot be cleaned with water, dissolve because of a lot of film at water, lens will be destroyed. CNC Milling