激光快速速成形系统中激光数控电源的总体方案设计

探讨在激光快速成形系统中激光电源的工作特性及其控制机理，根据激光快速成形系统对激光的要求，提出一种适于封离式ＣＯ２激光器的数控恒流电源的硬件结构和设计思想。该电源在ＬＯＭ上使用，证明适用于激光快速成形系统。     

激光直接金属堆积成形技术的研究与应用进展

阐述了激光直接金属堆积成形技术的原理、硬件系统和软件系统。重点介绍了激光直接金属堆积成形技术的国内外发展概况、研究热点和应用现状。阐述了激光直接金属堆积成形技术存在的主要问题，并对该技术的研究方向和应用领域进行了展望。     

金属粉末激光烧结快速成型技术的研究

激光快速成型技术是集计算机辅助设计、激光熔覆、快速成型于一体的先进制造技术,是传统加工成形方法的重要补充。介绍了金属粉末激光快速成型技术的研究现状和发展前景。     

飞秒激光微部件加工系统的软件设计

详细介绍了近年来发展起来的先进制造技术--激光快速成型技术;阐述了飞秒激光微部件加工系统的主要研究内容、硬件结构和主要选用的设备;叙述了上位机软件的主要模块及实现方法.该系统采用面向对象的编程方法,界面友好,操作简单,功能完善,模拟实验效果良好,具有较好的应用前景.     

新的激光快速成形方法及应用

针对目前主要激光快速成形方法的优缺点,提出一种基于三维实体边界分割的激光快速成形新方法.该方法将叠层实体制造(LOM)法主要进行激光二维轮廓线扫描和选择性激光烧结(SLS)法能够加工多种覆膜粉末材料的优点有机结合,能够克服SLS法加工效率低,成形件致密度、硬度、精度和表面粗糙度等性能较低的缺点.利用自主开发的快速成形系统,采用热像仪测温与Ansys模拟激光能量输入模型相结合的方法对工艺参数进行确定,对基于三维实体边界分割激光快速成形方法进行应用研究,实现三维实体的快速成形及金属零件的快速铸造,并通过无模具快速铸造的手段获得金属齿轮铸件.     

激光工程化净成形技术的研究

激光工程化净成形技术是近年发展起来的一种新的快速成形技术 ,它将选择性激光烧结和激光熔覆技术相结合 ,不需要浸渗、热等静压等复杂后处理工序即可快速获得致密度和强度均较高的金属零件。本文介绍一种激光工程化净成形实验系统的组成 ,分析并解决激光工程化净成形加工中的若干问题     

基于RP技术的激光诱导选择性化学沉积微细加工技术的研究

在介绍快速成形技术以及微机电系统与微细加工技术的基础之上,对比分析了一些基于快速成形技术微细加工方法的优缺点及其最新研究成果。对于激光诱导选择性化学液相沉积快速成形技术的研究,首先从整个的系统原理到工艺流程进行详细地论述,并指出此技术所存在的一些优缺点。在普通玻璃上进行了激光诱导选择性化学液相沉积铜的试验,成功地沉积出点、线和面并实现了分层累加的沉积。在从激光诱导化学液相沉积技术的沉积原理和反应机理的分析到反应速率及沉积速率模型的建立的基础之上,进一步论证了激光诱导选择性化学沉积快速成形技术在三维微细加工方面的应用上是可行的。     

变长线扫描激光烧结快速成型机控制系统

介绍了变长线扫描激光烧结快速成型技术原理,对自行开发的变长线扫描激光烧结快速成型机控制系统的硬件组成、软件组成及其工作原理、激光功率与线长的匹配技术进行了分析.     

激光直接金属堆积成形技术的研究与应用进展

阐述了激光直接金属堆积成形技术的原理、硬件系统和软件系统.重点介绍了激光直接金属堆积成形技术的国内外发展概况、研究热点和应用现状.阐述了激光直接金属堆积成形技术存在的主要问题,并对该技术的研究方向和应用领域进行了展望.     

激光快速成形系统中激光数控电源的总体方案设计

探讨在激光快速成形系统中激光电源的工作特性及其控制机理，根据激光快速成形系统对激光的要求，提出一种适于封离式CO2激光器的数控恒流电源的硬件结构和设计思想。该电源在LOM上使用，证明适用于激光快速成形系统。     

Direct additive laser manufacturing using gas- and water-atomised H13 tool steel powders

To date only gas-atomised tool steel powders have been used for direct laser additive manufacturing and the potential benefits of using water-atomised powders have not been explored. As the use of the process in the rapid tooling field is growing, there is a need to explore if the less expensive water-atomised materials can be realistically utilised. A comparative investigation is described, using gas- and water-atomised H13 powder deposited with a CO₂ laser and coaxial powder feed nozzle. Multiple layer wall dimensions, composition, microstructure, surface finish and hardness are related to process conditions and the causes of the observed phenomena are discussed. An energy-balance method is used to model the temperature of the powders and the results used to explain some of the effects. Results indicate that using the lower cost water-atomised powder still allows a metallurgically sound component to be built and does not significantly affect surface finish. The build rate is, however, lower and the water-atomised powder tends to produce slightly softer walls, attributable to a higher temperature during tempering of deposited material by subsequent laser passes.     

Metal Rapid Prototype Fabrication Using Selective Laser Cladding Technology

Non-metallic rapid prototyping has been successfully applied in several industries, but a metal rapid prototype is required for functional prototypes and tooling applications. A metal rapid prototype fabricated using selective laser cladding is presented in this paper. Laser cladding is one type of laser surface treatment process. During this process, an alloy is fused onto the surface of a substrate. Laser cladding devices, i.e. powder feeder, CNC workstation table, laser shutter, and shielding gas controller, were integrated to make automatically any cladding profile possible. The metal prototype was then fabricated layer by layer. This is called the selective laser cladding system (SLC). The fabrication of the metal rapid prototype using SLC technology is described and the detailed design and construction of the SLC is presented in this paper.     

汽车发动机零件的快速制造

介绍了最适用于发动机零件制作的选区激光烧结(简称SLS)方法,并将快速成型技术与传统的铸造技术进行有效的结合形成快速铸造技术--熔模快速铸造和快速砂型铸造,以快速制造复杂金属零件.     

飞秒激光双光子聚合三维微细加工技术及系统研发

阐述了飞秒激光双光子聚合（TPP）制造三维零件微快速原型技术和成形系统的搭建及其实现的理论基础,分析该技术的两大显著技术优势以及双光子吸收特性、双光子聚合工艺流程、成形材料及双光子触媒的特性,并在此基础上进行工艺参数影响分析和优化组合,给出初步实验结果,提出系统未来发展提升空间。     

分层实体制造激光光路分析与快速校准

文章介绍了分层实体制造激光快速成型机的光路系统组成，分析了光路系统偏差对零件尺寸形状误差的影响，最后介绍了浙江光路快速校准的方法。     

Application of laser joining process for elimination of stair steps in steel laminate tooling

Laminate tooling is a relatively fast and simple method of making large metal tools directly for various moulding processes in the rapid prototyping and manufacturing field. Metal sheets are usually cut, stacked, aligned and joined. In most cases, lasers are used only for the cutting of steel sheets in laminate tooling, but in this study, the use of the laser was expanded for improved laminate tooling. First, the laser was applied to eliminate the stair steps of steel laminates by filling them with molten filler metals. Then application of hard particles to molten filler metals for improved surface hardness of laminate tools was investigated. To achieve this goal, a CO₂ laser system composed of a CO₂ laser, a five-axis CNC table, an automatic feeding equipment of filler metal and flux and a personal computer was developed. Various experiments on filling stair steps and hardening were performed and the results were verified and estimated.     

<Emphasis Type="Bold">Laser Sintering of Silica Sand – Mechanism and Application to Sand Casting Mould</Emphasis>

Silica sand is commonly used in the foundry industry. With a high melting point of 160°C, the silica sand is normally sintered in a high-temperature furnace. However, silica with contents of calcium, aluminium, magnesium, and chlorine, etc. can form low-melting point eutectics. Therefore, a relatively low-power laser can be used to sinter the silica sand directly. The investigation of the mechanism and process for direct laser sintering of the silica sand, without any binder, is presented in this paper. Combined with rapid prototyping (RP) technology, the laser sintering of the silica sand can be used to directly fabricate a sand casting mould, called a rapid sand casting mould. By avoiding the time-consuming process of fabricating a pattern, the rapid sand casting mould process has the potential of further reducing the lead time for producing a casting product. Some important issues, such as the lead time of producing a sand mould, its accuracy, and surface finish, etc., are discussed.     

Nd:YAG激光器金属零件激光快速成型工艺研究

利用Nd:YAG1.1kW激光器和同轴送粉方式进行了金属零件激光快速成型工艺实验研究.叙述了激光快速成型制造系统的基本组成和实验方法;分析了主要工艺参数如:激光功率、扫描速度、送粉量以及Z轴增量对成型质量和形貌的影响.给出了在最佳工艺参数下得到的激光成型实例.     

Rapid prototyping machine based on ceramic laser fusion

This paper proposes an automatic machine using a new process, ceramic laser fusion, for rapid fabrication of ceramic parts. The machine comprises three parts: a laser scanning system, a green layer paving system, and a control system. In order to control the working procedure of layer paving and scanning process, a process computer is connected to an X–Y table, a PLC and a path/laser controller. An even green layer of 0.15 mm thickness could be paved accurately using ceramic slurry by a layer paving device. After drying by an infrared heater, the green layer could be fused to form a ceramic layer by a CO₂ laser and then a 3-D ceramic workpiece could be fabricated layer by layer automatically. The time spent on fabricating a 25×25×0.15 mm ceramic specimen was 3 min. The SEM micrograph of the melted ceramic layers shows that ceramic green layers can be fused together.