激光切割加工作為一種優(yōu)異的材料切割手段,激光加工因材料浪費(fèi)少、在規(guī)?;a(chǎn)中成本效應(yīng)明顯、對(duì)加工對(duì)象具有很強(qiáng)的適應(yīng)性等優(yōu)勢(shì),被越來越為鈑金生產(chǎn)者所接受。
在實(shí)際作業(yè)過程中,激光切割加工在厚板加工中穿孔時(shí)間占很大比重,各激光廠商紛紛開發(fā)了快速穿孔的技術(shù),較為有代表性的是高能穿孔(炸孔),這種方法的優(yōu)點(diǎn)是速度快,缺陷是不僅影響對(duì)小形狀的加工,穿孔時(shí)注入的巨大能量使板材溫度升高進(jìn)而影響接下來的整體切割過程。而用小功率脈沖進(jìn)行穿孔的話,時(shí)間很長(zhǎng),會(huì)導(dǎo)致切割的效率下降和單位成本的提高。
針對(duì)激光切割的這一問題,可以利用占空比小的高峰值脈沖激光,輔以噴射在材料表面上的不燃油以清除開孔邊緣附著物,控制脈沖的合理頻率邊冷卻邊穿孔。其特點(diǎn)是相對(duì)炸孔雖然時(shí)間稍長(zhǎng),但穿出的孔徑小且開孔邊緣無附著物以及入熱較低,便于接下來的正常切割加工,相比普通穿孔則效率提高了4倍。
激光切割加工中厚板時(shí)經(jīng)常會(huì)遇見切割斷面,這樣的切割不僅成品質(zhì)量受到質(zhì)疑,還會(huì)伴隨著過燒和嚴(yán)重的粘渣出現(xiàn),以致體現(xiàn)不出高價(jià)的激光加工機(jī)區(qū)別于其他切割手段的價(jià)值。
對(duì)于碳鋼來說改善切割斷面的重要因素是控制對(duì)板材的入熱并能保證激光照射部分的充分燃燒。對(duì)于不銹鋼來說改善切割斷面的重要因素則是光束的改良與輔助氣體的有效利用。亮面切割技術(shù)是改善了發(fā)振器和噴嘴所得到的結(jié)果。
Laser cutting is an excellent means of cutting materials. It has the advantages of less material waste, obvious cost effect in large-scale production, and strong adaptability to the processing object, is becoming more and more accepted by sheet metal producers. In the actual operation process, the laser cutting takes a large proportion of the perforation time in the thick plate processing, each laser manufacturer has developed the fast perforation technology one after another, the more representative is the high energy perforation (blow hole) , this method has the advantage of high speed, the defect is not only affect the small shape of the processing, punch into the huge energy to increase the temperature of the plate and then affect the overall cutting process. The use of low-power pulse piercing, then a long time, will lead to cutting efficiency and unit cost increase. To solve the problem of laser cutting, high peak pulse laser with small duty cycle and non-fuel oil injection on the surface of material can be used to remove the attachment on the edge of the hole and control the reasonable frequency of pulse while cooling and piercing. It is characterized in that the hole diameter is small, the edge of the hole is not attached and the heat input is low, which is convenient for the following normal cutting process. The cutting section is often encountered in the laser cutting process of medium and heavy plates. Such cutting is not only of questionable quality, but also accompanied by over-burning and serious slag sticking, so that does not reflect the high price of laser processing machine different from other cutting means of value. The important factor to improve the cutting section of carbon steel is to control the heat input into the plate and ensure the full combustion of the laser irradiation part. For stainless steel, the important factor to improve the cutting section is the improvement of beam and the effective use of auxiliary gas. The bright surface cutting technique is the result of improving the vibrators and nozzles.