玻璃的激光切割

在玻璃生产及加工领域,激光切割因其高精度、高速度、高质量、高效率等独特的优势成为玻璃切割领域的一项新技术。通过介绍玻璃的激光切割原理和研究现状,展望了激光切割的发展趋势,激光切割技术在玻璃行业特别是电子玻璃基板行业具有十分广阔的市场应用前景。     

柔性玻璃激光切割技术研究

通过对柔性玻璃各种切割方式断面的形貌分析,研究激光切割断面、自然断面、玻璃刀机械切割以及化学腐蚀切割断面的不同,分析得出激光切割的优点非常适合柔性玻璃的切割。另外,对比不同激光光源的切割,分析激光烧蚀和激光应力切割的不同,得出不同激光对柔性玻璃切割的影响,对柔性玻璃激光切割系统的组成和工艺的选择具有指导意义。     

柔性玻璃弯曲断裂的研究分析

在制备柔性玻璃的过程中,出现了玻璃切割及弯曲时易断裂的现象。通过对刀轮切割及激光切割形貌分析,刀轮切割断口表面缺陷较少。对切割玻璃边部进行800℃火抛光处理,可使0.1 mm柔性玻璃曲率半径达到75 mm。     

塑料加工最新技术——激光加工

简要介绍了塑料加工技术——激光加工技术的起源、发展过程及应用领域。详细介绍了塑料的激光焊接技术、激光打孔技术、激光标志技术和激光切割技术的应用技术、方法特点和发展趋势。     

恢复玻璃本征强度的工艺概述

玻璃激光切割不产生玻璃边部缺陷和微裂纹,对玻璃起增强作用明显而又省掉玻璃加工中心和节约水资源;其与传统的酸洗、物理钢化、化学钢化、涂(镀)膜组合后的增强效果更佳,一种新的玻璃材料表面等离子体原位处理技术也已成熟,以上方法技术有选择性地结合以达到恢复玻璃本征强度的目的.     

激光切割技术在海洋工程建造中的应用研究

随着全球经济技术的快速发展,激光切割技术的发展也快速的进入到一个崭新的阶段。受益于激光切割技术的平民化,尤其是大功率激光器的研发及造价的下降,激光切割在中薄板切割中的优势凸显,其在海洋工程建造大局中的扮演的角色必然将愈来愈重要。本文通过介绍激光切割,分析其优势及应用定位,研究其在海工工程中的应用前景。     

碳纤维复合材料激光切割综述

综述了激光切割碳纤维复合材料的国内外研究进展,阐述了激光切割碳纤维复合材料的特点、表面质量及其影响因素,总结了激光切割碳纤维复合材料的表面质量的研究进展,最后对激光切割碳纤维复合材料的发展趋势进行了展望。     

玻璃切割精度的控制及改善方法

在玻璃生产过程中,玻璃的切割精度直接影响产品的质量.阐述了玻璃切割时横切机的工作原理,分析了测速轮的精准性、阻力、玻璃带波动及信号传递等因素对玻璃切割精度的影响,提出了提高玻璃切割精度的解决方法.     

硅酸盐激光玻璃

结合硅酸盐激光玻璃的最新进展和应用,系统、全面地介绍了硅酸盐激光玻璃的基本结构、性质、制备和研究方法等一系列问题,总结了近年来硅酸盐激光玻璃工业发展的理论和实验基础性研究,对硅酸盐激光玻璃可能的发展方向进行了展望.     

基于冻结浆料的分层实体制造法加工陶瓷坯体

提出了一种新型陶瓷增材制造方法,浆料由陶瓷粉末、有机粘结剂和去离子水构成,单层生坯的加工过程包括:铺料、冷冻和激光扫描,层层累积成型后,将冻结状态坯体置于冷冻干燥机中干燥,得到陶瓷生坯;分析了激光加工参数和浆料固含量对于激光扫描过程的影响.结果表明:采用激光扫描图形轮廓的方式,避免了激光辐照对材料内部结构的破坏;通过与冷冻干燥技术的结合,充分保留了片层状的孔隙结构;随着激光能量密度的增大,激光扫描线的宽度和激光切割的深度增大;随着浆料固含量的增加,受陶瓷颗粒对激光能量产生散射作用的影响,激光的切割深度减小.     

Laser cutting of float glass during production

Studies were conducted to determine the strength and thermal stability of samples of glass with edges obtained by cutting a moving ribbon of float glass by mechanical and laser cutting. The advantage of laser cutting was demonstrated.     

Mechanically inspired laser scribing of thin brittle materials

Laser processing of thin flexible ceramics and glasses is challenging due to the incurred brittleness and unfavorable thermal and optical properties of such materials. We describe an alternative laser cutting method which utilizes surface stress raisers to cleave brittle substrates along a defined path. An ultrashort laser source is used to precisely pattern a plurality of aligned elliptical recesses on the material surface. The apex of an ellipse concentrates applied tensile stresses. Depending on the elliptical dimensions, the achievable stress concentration factor can be up to 50. The orientation of the ellipses defines a preferred scribing path. The technique was successfully applied to thin flexible yttria stabilized zirconia ceramic and borosilicate glass substrates. The form and properties of the material play an important role during the fracture process. Polycrystalline ceramics were found to accurately auto cleave along the path due to stresses produced during the laser ablation. The resulting fractured surface is of higher quality and strength than surfaces cut using full body laser cutting techniques, while the crystalline phase is preserved. The optical setup is simple, low cost, and compatible with roll‐to‐roll manufacturing.     

High quality full ablation cutting and stealth dicing of silica glass using picosecond laser Bessel beam with burst mode

Glass cutting is widely used in many fields, such as aerospace and integrated electronics. To meet requirements of high-quality glass cutting, methods of full ablation cutting and stealth dicing of silica glass using picosecond laser Bessel beam are studied in this paper. Position synchronized output function of laser source and burst mode (BM) can flexibly adjust drilling spacing and the number of sub-pulses during processing. Through experimental research and theoretical analyses, effect of hole spacing, BM, laser power, and defocusing distance on the roughness of the cross-sections of cutting samples are investigated. The optimal combination of full ablation cutting parameters is obtained with the minimum roughness of the cross-section of 355 nm. To expand the application range of Bessel beam glass cutting, stealth dicing process is developed. Process parameters selection strategy of stealth dicing is obtained. Main parameter that affects the effect of stealth dicing is the defocusing distance. Aforementioned methods may provide simple, efficient, and high-quality full ablation cutting and stealth dicing technologies for glass materials.     

Influence of tapes’ properties on the laser cutting process

Ceramic tapes are used to build 3-dimensional components and microsystems in layer manufacturing. The tapes are individually printed and structured before being stacked and laminated. The structuring process of the tapes affects the maximal resolution of fluidic channels, suspended bridges and beams, which in turn determines the scale of miniaturization of the produced components. The aim of this paper is to investigate if the tape composition can be optimized to improve the cutting resolution of laser cutting, which is a very flexible tool for micromachining. Using the Siemens star pattern, the laser cutting resolution was measured for alumina green tapes of different binder compositions with different laser settings. For all tapes the resolution was better the higher the laser beam velocity. At higher velocity though, a higher number of cutting cycles is necessary to cut the tape. The laser cutting resolution depends on the binder composition, but the laser parameters must also be optimized to achieve high cutting resolution.     

Cutting characteristics of dental glass ceramics during in vitro dental abrasive adjusting using a high-speed electric handpiece

Machinability is an important characteristic of dental ceramics for restorative dentistry because machining is not only commonly employed in dental CAD/CAM systems but also essential in dental adjustments for occlusal fitting and restorative quality. This paper reports on an in vitro study on machinability of dental ceramics by quantifying cutting characteristics of feldspar and leucite glass ceramics in simulated dental adjusting using a high-speed electric handpiece and diamond burs. Cutting forces, force ratio, energy, surface integrity and bur topography were evaluated as functions of clinically relevant cutting conditions. The results indicate that tangential and normal forces and specific cutting energy for both materials exhibited significant dependences (p<0.01) on both the bur depth of cut and the bur feed rate. Surface roughness showed a weak influence by the choice of the material (0.05>p>0.01) but no correlations with the cutting conditions applied (p>0.05). At the slower feed rates or smaller depths of cut the cutting behaviors for the two materials were very similar in terms of cutting forces and specific cutting energy. At the deeper depths of cut or faster feed rates, normal forces for leucite glass ceramic were significantly higher than those for feldspar glass ceramic (p<0.01). However, leucite glass ceramic produced better cutting surfaces with less fracture areas compared with feldspar ceramic due to its lower index of brittleness and higher force threshold for brittle–ductile transition. This research provides a methodological qualification in evaluating cutting characteristics of dental ceramics and quality control in clinical dentistry.     

A Study of Thermal Cutting of Glass

Thermal stresses due to a hot-air jet impinging on a glass sheet can be used to stably initiate and attract a crack toward the jet axis. Relative motion between the jet and glass sheet then can be used to cut the glass sheet. This paper presents a theoretical and experimental study of this process for straight cuts. The model consists of sequentially coupled thermal and stress analyses for different cutting velocities. The stress field is used to compute stress-intensity factors for different assumed positions of a crack behind the moving air jet. The minimum air temperature for cutting and the stand-off distance of the crack behind the nozzle increase as the cutting velocity increases. The various process and material parameters that control the process-including cutting speed, air temperature, and sheet thickness-are reduced to dimensionless numbers. Theoretical results, presented as a map in the space of these dimensionless numbers, describe the conditions under which cutting is possible. An experimental cutting apparatus has been constructed and used to validate the heat-transfer analyses. Cutting experiments on this apparatus are in good agreement with the model.     

High wear-resistance characteristic of boron-doped nano-polycrystalline diamond on optical glass

Boron-doped nano-polycrystalline diamond (B-NPD) uniformly containing boron atoms in the diamond lattice has been successfully produced by direct conversion sintering under ultra-high pressure and high temperature using boron-doped graphite as a starting material, and its wear properties on optical glass materials have been investigated. The chemical wear of B-NPD sliding on glass was highly suppressed under sliding conditions where undoped NPD is worn considerably by chemical reaction with glass because the frictional resistance of NPD decreased and its sliding performance was improved by adding boron. In addition, because B-NPD has electrical conductivity, tribo-microplasma damages attributed to frictional electrification were not observed. Thus, the wear resistance of B-NPD on glass materials was improved greatly in comparison with that of undoped NPD. These results indicate that B-NPD has outstanding potential as a cutting tool material for high-performance and high-precision cutting on various types of glass, nonconductive ceramics and rigid plastics which are difficult to cut by conventional diamonds because of tribo-chemical wear or tribo-electrical wear.     

Cutting and Machining Energetic Materials with a Femtosecond Laser

A femtosecond (fs) laser has been used as a tool for solving many problems involving access, machining, disassembly, inspection and avoidance of undesirable hazardous waste streams in systems containing energetic materials. Because of the unique properties of the interaction of ultrashort laser pulses with matter, the femtosecond laser can be used to safely cut these energetic materials in a precise manner without creating an unacceptable waste stream. Many types of secondary high explosives (HE) and propellants have been cut with the laser for a variety of applications ranging from disassembly of aging conventional weapons (demilitarization), inspection of energetic components of aging systems to creating unique shapes of HE for purposes of initiation and detonation physics studies. Hundreds of samples of energetic materials have been cut with the fs laser without ignition and, in most cases, without changing the surface morphology of the cut surfaces. The laser has also been useful in cutting nonenergetic components in close proximity to energetic materials.     

The effect of sample preparation on the mechanical properties of nylon 66

Cutting test specimens from molded plaques is commonly used in mechanical testing. The mechanical properties of these cut specimens may be affected by cutting process as it could introduce extrinsic flaws and thermal effects on cut edge surfaces. The objective of this experimental research is to determine how band saw cutting affects the flexural and impact strengths of 33% short glass fiber (GF) reinforced polyamide 66 (PA66) and unreinforced PA66. The specimens for the flexural and impact tests were obtained by cutting molded plaques using different blade types, blade speeds, feed rates, and levels of polishing. Results were compared with those from uncut specimens. Surface morphologies of the specimens' cut edges (photographs and roughness) were assessed using Scanning Electron Microscopy and PRK Perthometer, respectively. The results indicated that higher flexural and impact strengths of cut specimens of 33% GF reinforced PA66 were achieved with high blade speed, low work piece feed rate and using a high number of teeth per unit length. For unreinforced PA66, higher impact strengths were achieved at low blade speeds and work piece feed rates.     

高能量密度束流在玻璃加工中的应用

高能量密度束流，如激光束、电子束、离子束，已用于玻璃的清洗、抛光、切割、打孔、刻花、内雕等加工过程。阐述了高能量密度束流的特性及其加工玻璃工艺，并指出了发展方向。