碳纤维复合材料激光切割实验研究

为了研究激光切割参数对碳纤维复合材料(CFRP)切割表面质量的影响,利用Nd:YAG固体毫秒脉冲激光器,对碳纤维复合材料进行了激光切割实验。通过对普通碳纤维复合材料以及增加炭黑颗粒碳纤维复合材料进行激光切割,获得了相应的碳纤维复合材料的切割表面质量,并对激光切割过程产生的热影响区进行了分析。实验结果表明,普通碳纤维复合材料激光切割后存在严重的层离现象,同时切割面会产生裂纹,影响碳纤维复合材料的抗疲劳性能;碳纤维复合材料增加炭黑颗粒后进行激光切割,能够获得良好的切割质量,切割面无裂纹以及无层离现象,切割部分容易分离,有效改善其激光切割性能。     

激光切割CVD金刚石厚膜的工艺研究

本文利用Nd:YAG激光器对0.4mm厚的CVD金刚石膜进行切割,用扫描电子显微镜(SEM)研究了激光脉冲能量、脉冲宽度和脉冲频率等工艺参数对金刚石厚膜切割的影响。研究结果表明,在脉冲电流高于200A和减小脉冲电流至150A、脉冲宽度为2ms时能一次性切透金刚石厚膜但切割断面存在许多微裂纹和缺陷。增大脉冲频率有利于提高切割断面的平整度;采用二次切割比一次切割可得到更为平整的切割断面,断面粗糙度Ra可达到1μm。     

手提式钢缆激光切割系统的设计

介绍了一种手提式光纤传输钢缆激光切割系统。以脉冲固体激光器作为光源,采用光纤进行柔性传输,设计了切割钢缆的专用夹具,研究了钢缆的切割工艺。通过优化放电电流、脉冲频率、脉冲宽度、辅助气压等参数,该系统可满足直径12mm内的钢缆的切割要求,提供了切割钢缆的新方法。     

皮秒脉冲隐形切割碳化硅晶圆实验研究

为了实现高速度切割碳化硅（SiC）晶圆,采用自行研制的高能量皮秒脉冲光纤激光器进行了隐形切割实验。依据切片的截面形貌、表面热损伤区和边缘直线度,分析了皮秒激光器的切割结果,并探究了单脉冲能量和扫描速度对切片质量的影响。结果表明,当使用中心波长为1 030 nm、重复频率为100 kHz、单脉冲能量为20μJ、脉冲宽度约为100 ps的皮秒脉冲隐形切割360μm厚度的SiC晶圆时,切片的质量能够满足实际应用要求,且激光的扫描速度可达400 mm/s,相应的切割速度为44.44 mm/s,高于其他相关报道。     

调Q脉冲CO2激光切割Si3N4工程陶瓷的机理研究

采用调Q脉冲CO2激光器对Si3N4工程陶瓷进行了切割试验.在计及切口烧蚀前沿形状和高斯光束空间能量分布的前提下,采用简化的二维模型,针对气化切割过程,在能量平衡基础上,建立了一个脉冲激光切割数学模型.试验结果表明,采用高速多次重复走刀工艺可实现无损伤激光切割.     

激光切割玻璃

长期以来,切割玻璃大都采用机械的手段,如用机械力的作用,或用温度突变的方法,还可用金刚石工具切割,但上述方法不是精度不高,就是花费太大。最近东德蔡斯厂研究用二氧化碳激光器来切割玻璃。采用二氧化碳激光器是因为它波长在10.6微米,效率高,可连续或脉冲式工作。     

快速轴流型与密封型CO2激光器超脉冲特性研究

快速轴流型CO₂激光器和密封型CO₂激光器超脉冲运转时,能够获得前沿迅速上升、脉宽窄、峰值功率高的激光脉冲输出,在激光加工和激光医疗等领域有重要应用价值。本文从理论和实验两个方面对快速轴流型与密封型CO₂激光器超脉冲特性进行了研究,设计并研制了适合CO₂激光器超脉冲运转的控制电源,在国内首次实现了快速轴流型与密封型CO₂激光器的超脉冲运转。     

高强耐磨钢板切割工艺研究

高强耐磨钢一般硬度越高,耐磨性越好。耐磨钢通过合理的合金成分匹配,同时借助淬火及低温回火获得强度高、耐磨好的力学性能,但随着钢板硬度和厚度的升高,氧气燃料火焰切割时容易出现延迟裂纹,此裂纹为氢致裂纹。通过预热至一定温度后慢速切割,可以很好地解决切割裂纹问题。     

科技消息

长期以来,切割玻璃大都采用机械的手段,如用机械力的作用,或用温度突变的方法,还可用金刚石工具切割,但上述方法不是精度不高,就是花费太大。最近东德蔡斯厂研究用二氧化碳激光器来切割玻璃。采用二氧化碳激光器是因为它波长在10.6微米,效率高,可连续或脉冲式工作。大家知道,激光束通过聚焦,功率密度可达到每平方厘米亿瓦,假设使如此高温的     

基于机器视觉的便携式激光切割系统设计

电力铁塔安装过程中两角钢预置孔位常出现错位,螺栓无法穿过,为解决这一问题,需要采用激光切割机进行扩孔切割。提出并设计了一套基于机器视觉的便携式激光切割打孔系统,实现了对远距离、高空铁塔上错位孔位的切割打孔作业。系统主要由激光器系统、控制与执行系统、传输线缆三部分构成。为保证设备便携,激光器系统由多个可拆解和组合的模块组成,设计并实现了将多束小功率激光器进行合束,从而达到大功率输出,实现高能量切割作业。控制与执行系统利用机器视觉进行图像采集与切割路径规划,以实现在地面完成对高塔上切割过程的监控和引导伺服系统完成自动切割。实验结果表明,机器视觉算法准确性高,切割效果较为理想。     

Characteristics of laser assisted machining for silicon nitride ceramic according to machining parameters

This paper describes the Laser Assisted Machining (LAM) that cuts and removes softened parts by locally heating the ceramic with laser. Silicon nitride ceramics can be machined with general machining tools as well, because YSiAlON, which was made up ceramics, is soften at about 1,000°C. In particular, the laser, which concentrates on highly dense energy, can locally heat materials and very effectively control the temperature of the heated part of specimen. Therefore, this paper intends to propose an efficient machining method of ceramic by deducing the machining governing factors of laser assisted machining and understanding its mechanism. While laser power is the machining factor that controls the temperature, the CBN cutting tool could cut the material more easily as the material gets deteriorated from the temperature increase by increasing the laser power, but excessive oxidation can negatively affect the quality of the material surface after machining. As the feed rate and cutting depth increase, the cutting force increases and tool lifespan decreases, but surface oxidation also decreases. In this experiment, the material can be cut to 3mm of cutting depth. And based on the results of the experiment, the laser assisted machining mechanism is clarified.     

工程陶瓷的激光加热辅助切削技术

激光加热辅助切削工程陶瓷技术即使用激光作为外加热源先于刀具加热软化陶瓷工件,然后再使用刀具将软化的材料去除。较高的剪切变形区温度降低了陶瓷材料的屈服应力和硬度,陶瓷变形特征从脆性转变为塑性或者准塑性,从而提高切削效率,延长刀具使用寿命,有望解决陶瓷加工中的低效率和高成本现状。从激光加热辅助切削工程陶瓷研究进展、激光束的整合,以及切削机理等方面,对激光加热辅助加工工程陶瓷做了较为全面的论述。     

Ultrashort pulse laser micromachined microchannels and their application in an optical switch

The capability of direct writing makes ultrashort pulse laser significant in the microfabrication of MEMS devices based on polymer and glass. In particular, nanosecond and femtosecond lasers are able to transfer the adequate energy in femtosecond intervals for the removal of the materials. Because of its advantages, just like the small feature size, smooth finishing surface, flexible structuring and the minimum thermal effect, ultrashort pulse lasers have become a convincing technique with the high peak power. This paper presents the femtosecond laser machining results of the polycarbonate, aluminosilicate glasses and nanosecond laser machining of aluminosilicate glasses. The microchannels with the critical micron-scale dimensions and the sub-micron scale surface roughness were achieved by the optimized operating parameters of the laser. The major influence factors such as cutting speed, power energy, and power stability were analyzed to obtain the optimized parameters for the fabrication of the microchannels for a bubble switch. The ultrashort pulse laser micromachining was applied in the prototype of a bubble optical switch. By miniaturization of the structure of the microchannel, the switch speed can be promisingly improved.     

高速切削刀具材料及其与工件匹配研究

实现高速切削加工,刀具材料是关键。目前国内外用于高速切削加工的刀具材料主要有聚晶金刚石(PCD)、立方氮化硼(CBN)、陶瓷、TiCN基金属陶瓷和涂层刀具等。本文介绍了这些高速切削刀具材料各自的特点和应用范围,分析了高速切削刀具材料与工件材料的匹配,并阐述了针对常用工程材料的高速切削加工和刀具材料的合理选择。     

水辅助激光加工技术的实验研究

介绍水辅助激光打孔和切割实验研究。研究表明 ,用毫秒级YAG脉冲激光对不锈钢和Al2 O3 陶瓷加工时 ,熔屑易从加工区排出 ,有助于提高加工的表面质量 ;加工单晶硅时 ,加工表面易产生微裂纹 ,使加工质量变差。激光通过水层时 ,有能量损失 ,水层深度越深 ,能量损失越大。     

Parametric analysis and optimization of Nd:YAG laser micro-grooving of aluminum titanate (Al2TiO5) ceramics

Pulsed Nd:YAG Laser offers an excellent role for various micro-machining operations of a wide range of engineering materials such as ceramics, composites, diamond etc. The micro-machining of ceramics are highly demanded in the present industry because of its wide and potential uses in various field such as automobile, electronic, aero-space, and bio-medical engineering applications etc. Aluminum titanate (Al₂TiO₅) has tremendous application in automobile and aero engine industry due to its excellent thermal property. The present research paper deals with the response surface methodology based mathematical modeling and analysis on machining characteristics of pulsed Nd:YAG laser during micro-grooving operation on a work piece of aluminum titanate. In this present study, lamp current, pulse frequency, pulse width, assist air pressure and cutting speed of laser beam are considered as machining process parameters during pulsed Nd:YAG laser micro-grooving operation. The response criteria selected for analysis are deviation of taper and deviation of depth characteristics of micro-groove produced on a work piece made of aluminum titanate (Al₂TiO₅). The analysis of variance test has also been carried out to check the adequacy of the developed regression mathematical models. The optimal process parameter settings are assist air pressure of 1.3 kgf/cm², lamp current of 20.44 amp, pulse frequency of 1.0 kHz, pulse width of 10% of duty cycle, and cutting speed of 10 mm/s for achieving the predicted minimum deviation of taper and deviation of depth of laser micro-groove. From the analysis, it is evident that the deviation of taper angle and deviation of depth of the micro-groove can be reduced by a great extent by proper control of laser machining process parameters during micro-grooving on aluminum titanate (Al₂TiO₅).     

CO2激光切割非金属材料理论模型

基于能量平衡方程,考虑高斯光束分布,建立了CO2激光切割高吸收率非金属材料的解析模型。理论分析和试验结果表明切割深度随着切割速度的减小而增加,随着激光功率的增加而增大。该模型适合12mm以下薄板切割和12~20mm较厚板的大功率(>400W)高速(>1.0m/min)切割。经过模型修正后,也可适合厚板(>20mm)切割。     

碳纤维增强复合材料水导激光切割试验研究

采用正交试验方法对影响水导激光切割碳纤维增强复合材料（CFRP）的关键工艺参数进行了深入研究,得出了进给速度、水射流速度、脉冲频率和激光功率对切割CFRP的影响规律,并用直接对比法和极差分析法所得最优参数进行单次划槽切割对比。研究结果表明：在极差分析法所得最优参数下切割CFRP时,切缝深度增大3.2%、切缝宽度减小9.2%、切缝锥度减小11.8%、线粗糙度减小40.2%。通过与干式激光加工方法对比发现,水导激光加工技术在切割CFRP方面优势明显,由于水射流的冲刷和冷却作用,材料切割表面几乎无热影响区和纤维拔出。另外,采用正交试验所得最优工艺参数实现了4 mm厚度CFRP的无锥度切割。