光纤激光切割厚碳钢板小孔的工艺研究

本文以FL513i型数控激光切割机为平台,研究了高功率光纤激光切割机在切割厚碳钢板小圆孔时的切割工艺,通过对工艺参数的调整,研究了光纤激光功率、切割速度、氧气压力、焦点位置对切割质量的影响,总结出优质切割厚碳钢板小孔的工艺参数组合,解决了光纤切割厚碳钢板质量差的问题,从而使光纤激光在切割厚碳钢板中的应用更为广泛。     

光纤激光切割机特殊工艺设定对切割质量的影响

通过对激光切割机切割质量的大量试验研究,从激光切割加工特殊工艺要求来分析穿孔技术、引线设置和拐角设置等特殊工艺设定对切割质量和加工效率的影响。     

Al_2O_3陶瓷激光切割工艺研究

为了探究Al_2O_3陶瓷的激光切割工艺特性,采用Nd:YAG激光器对Al_2O_3陶瓷进行加工试验。先通过打孔试验计算获得Al_2O_3陶瓷的激光烧蚀阈值,再通过切割试验分析激光功率、切割速度、脉冲频率、离焦量等工艺参数对切割质量的影响规律。结果表明:通过优化激光切割工艺参数,可在保证切割效率的同时,提高Al_2O_3陶瓷的切割质量。     

激光高速切割工艺对薄板切割质量的影响

对薄板的激光高速切割工艺进行了研究,重点探讨激光高速切割工艺中激光功率、切割速度对切缝宽度与切割质量的影响。研究表明:激光高速切割时,切缝宽度随着切割速度的增加而减小,随着激光功率的增加而相应增加。在保持切割速度不变的情况下,当激光功率较小时,薄板切不透,熔渣留在切缝中,切割质量差;随着激光功率的增加,切割质量提高,但是随着激光功率继续增加,切缝处过烧造成切割质量降低。对于厚度相同的薄板,激光功率小于1 k W时,最佳切割速度的幅度因子为0.95;当激光功率介于1~2 k W之间时,幅度因子为0.64;当大于2 k W时,幅度因子为0.25。     

不锈钢板材激光切割工艺分析

研究了不锈钢板材激光切割工艺中重要因素对切割质量的影响,即激光功率、切割速度对割缝表面粗糙度、割缝宽度、割缝挂渣情况以及割缝热影响区宽度的影响情况,确定了最佳的切割工艺参数,为不锈钢板材激光切割提供参考,具有一定的实用价值。     

工艺参数对激光切割1060铝板切割质量的影响

通过正交试验研究激光功率、切割速度、偏焦量、辅助氧气气压等工艺参数对激光切割1060纯铝板切割面质量的影响,研究发现:最佳切割工艺参数为激光功率为900 W,切割速度为40 mm/s,偏焦量为-0.5 mm,氧气气压为0.8 MPa;增大激光功率和氧气压力,降低切割速度和减小偏焦量有助于提高切割质量;切割界面一般由光亮区和重熔区组成,在一定的切割工艺参数下切割面可出现单一区域。     

血管支架的激光加工工艺及研究进展

阐述了血管支架的发展历程、加工方法以及激光切割等,详细介绍了关于激光切割工艺参数对血管支架切割质量的影响方面的研究工作,具体包括Nd∶YAG激光、光纤激光以及皮秒和飞秒激光。     

钨合金薄板单模光纤激光切割

钨合金是高熔点材料,其激光热切割是难点。利用单模光纤激光作为切割热源,切割板厚0.9 mm的钨合金(合金成分:93W-4.9Ni-2.1Fe),探讨激光切割工艺参数及其切口质量。试验结果表明,在切割激光功率500 W、切割速度0.5 m/min、切割气体(氮气)压力0.8 MPa的条件下,切割缝宽约102μm,切割缝质量较好。在此激光切割工艺参数的基础上,若降低切割速度,切割缝宽度增大;若提高切割速度,无法获得良好的切割质量;若降低切割气体压力,无法获得良好的切割质量;若增加切割气体压力,对减小切割缝宽度及改善切割质量基本没有影响。     

基于响应面法的水导激光加工碳纤维复合材料工艺参数优化

为了更好地采用水导激光加工碳纤维复合材料，基于响应面法设计实验，研究了工艺参数对切割质量指标的影响规律和切割质量对工艺参数的敏感性，并以热影响区、锥度、有效切割速度为目标进行了优化。结果表明：激光峰值功率对热影响区和锥度的影响显著，而切割速度和切割次数对有效切割速度的影响显著；当在切割速度2.35 mm/s、激光峰值功率324.45 W、切割次数6次时，水导激光切割碳纤维复合材料表面质量较好。     

激光切割吸种盘的工艺研究

对吸种盘进行激光切割试验,探讨其工艺特点,分析不同的切割参数如激光功率、切割速度、辅助气体压力对切割质量的影响,给出Nd:YAG激光器切割吸种盘的具体方法.实验结果表明,只要工艺参数选择适当,可获得很好的切口质量,且能提高生产效率.     

激光切割表面质量比照判别与控制方法

提出了激光切割表面质量比照判别的方法与标准，通过调整激光切割参数，控制激光切割表面质量等级，解决了激光切割技术在更广泛范围内应用的技术关键，从而保证了在一定范围内实现激光切割加工一次性达到加工技术精度要求。     

中厚钢板大功率固体激光切割模式

对30mm厚钢板进行大功率固体激光切割试验,研究了主要工艺参数对切割特性的影响,揭示了中厚板激光切割的传热机理.结果表明,中厚板激光切割时呈现窄缝和宽缝两种切割模式,氧气压力和激光离焦量对窄缝-宽缝切割模式转变有很大的影响.窄缝横截面呈现出较平直的"I"型,宽缝横截面呈现出上宽下窄的"V"型.     

Analysis and prediction of laser cutting parameters of fibre reinforced plastics (FRP) composite materials

A theoretical model is presented considering the spatial distribution of the laser beam, interaction time between the laser and the work material, absorption coefficient of the laser beam at the laser wavelength and the thermal properties of the material. It is assumed that the laser energy is absorbed through the entire thickness of the material. The developed model predicts the various parameters in laser cutting of composite materials such as kerf width at the entry and at the exit, material removal rate and energy transmitted through the cut kerf. The theoretical analysis also determines the position of the beam with respect to the cutting front. Experiments for different laser and material combinations to evaluate the effects of cutting parameters on the cut quality were carried out to compare with the predicted results. The results obtained show very good agreement.     

Evaluation of cut quality of fibre-reinforced plastics-A review

This paper presents an overview of the development in laser cutting of fibre-reinforced plastics materials. Important aspects of laser cutting process are identified and discussed. Analytical and experimental findings are cited and critically assessed. This paper suggests that simulation of laser cutting parameters is required not only to reduce the heat-affected zone but also to improve the laser cut quality with respect to surface quality and dimensional accuracy. It is recommended that research effort be directed towards contour cutting and sharp comer cutting to make the laser more applicable in industries.     

50CrV钢螺丝刀刃口的激光淬火工艺优化与组织性能特征

为提高螺丝刀头刃口硬度与耐磨性,延长其使用寿命,在已做激光淬火薄壁件预试验基础上,采用大功率光纤耦合半导体激光器于螺丝刀刃口上进行激光淬火试验。利用光学显微镜、显微硬度计、摩擦磨损试验仪等试验测试仪器,分析刃口激光淬火区域组织形态特征、显微硬度及耐磨损性能,确定螺丝刀刃口激光淬火可行的工艺参数。试验结果表明:激光淬火后刃口由完全淬透区、过渡区、基材3部分组成,完全淬透区显微组织为针状马氏体与残留奥氏体,过渡区由马氏体与回火索氏体组成。刃口激光淬火合理工艺参数为激光功率600 W、扫描速度900 mm/min。激光淬火后刃口截面平均硬度为805.7 HV0.3,相对淬火前提高了177.4 HV0.3,表层硬度值达到816.7 HV0.3,相对淬火前提高了188.4 HV0.3。淬火后刃口表面磨损量为0.5 mg,为基材磨损量的27.8%,稳定摩擦因数为0.25,为基材稳定摩擦因数的65.8%。激光淬火工艺能有效提高螺丝刀刃口的显微硬度与耐磨性,可用于螺丝刀刃口表面性能强化。     

An investigation of energy loss mechanisms in water-jet assisted underwater laser cutting process using an analytical model

The water-jet assisted underwater laser cutting processes has relatively low overall efficiency compared to gas assisted laser cutting process due to high convective loss in water-jet from the hot melt layer and scattering loss of laser radiation by the water vapour formed at the laser–workpiece–water interaction region. However, the individual contribution of different losses and their dependency on process parameters are not fully investigated. Therefore, a lumped parameter analytical model for this cutting process has been formulated considering various laser–material–water interaction phenomena, different loss mechanisms and shear force provided by the water-jet, and has been used to predict various output parameters including the maximum cutting speed, cut front temperature, cut kerf and the loss of laser power through different mechanisms as functions of laser power and water-jet speed. The predictions of cutting speed, kerf-width and cut front temperature were validated with the experimental results. The modeling revealed that the scattering in water vapour is the dominant loss mechanism, causing ~40–50% of laser power loss. This also predicted that the percentage losses are lower for higher laser powers and lower water-jet speeds. In order to minimize the deleterious effect of vapour, dynamics of its formation due to laser heating and its removal by water-jet was experimentally studied. And, the cutting was done with modulated power laser beam of different pulse on- and off-times to determine the pulse on-time sufficiently short to disallow growth of vapour layer, still cutting be effected and the off-time enough long for water-jet to remove the vapour layer from the interaction zone before next pulse arrives. Compared to CW laser beam the modulated laser beam of same average power yielded higher process efficiency.     

Experimental and theoretical investigation of fibre laser crack-free cutting of thick-section alumina

A major challenge in laser fusion cutting of thick-section ceramics is to overcome the thermal-stress induced cracking, which leads to catastrophic breakdown of the material integrity. In order to achieve crack-free cutting of ceramics, it is important to understand the mechanism of the transient temperature field and resulting stress distribution effect on crack formation. In this paper, both experimental and theoretical investigations are reported to understand crack formation characteristics in fibre laser cutting of thick-section Al₂O₃ ceramics. A three-dimensional (3D) finite element (FE) model for simulation of the transient temperature field and thermal-stress distribution together with material removal in laser cutting was developed. Crack formation characteristics were predicted by the model and validated by experiments. The effects of four process parameters i.e. laser peak power, pulse duration, pulse repetition rate and feed rate on temperature field, resulting stress distribution and potential crack formation were also investigated in this work. The study indicates that a transition from compressive to tensile stresses can be resulted in as the laser cutting parameters change, which is beneficial to resist the crack formation. Based on the experimental and numerical investigations, the process parameters were optimised and the fibre laser crack-free cutting of 6-mm-thick alumina was demonstrated for the first time.     

钛合金的激光切割

研究了不同辅助气体和工艺参数对激光切割钛合金板的影响，分析了激光切割切缝的断面特征和热影响区特点。试验结果表明，用氩气作辅助气体，切割质量最好；激光功率和切割速度对切缝宽度和热影响区宽度有一定影响；切缝断面可分为形貌不同的两个区，两区之间有明显界线；切缝上表面和下表面热影响区宽度不同，特点为上窄下宽。     

Ti-23Al-17Nb合金激光切割工艺研究

对一种金属间化合物Ti-23Al-17Nb合金的激光切割性进行了初探。试验结果表明只要工艺参数适当，可获得较好质量的切口。切缝质量可以满足随后激光拼焊的要求。