高分辨率快速成形系统运动精度研究

快速成形系统升降工作台的运动精度是成形系统实现高精度制作的基础,对高分辨率激光快速成形系统的升降工作台运动精度进行测试研究.测试结果表明:工作台定位精度为6.4μm,单向重复定位精度为6.4μm,达到设计要求.还对工作台在向上进给和向下进给过程中,单向定位系统偏差及单向重复定位精度有明显差异的问题进行了研究,发现工作台的受力状态不同是出现以上问题的主要原因.     

CPS紫外光固化快速成形系统的研究与开发

从光固化成形的机理出发,提出以特定紫外光源取代激光器,降低成形系统的设备价格和使用成本,并介绍了据此开发的紫外光固化快速成形机,分析了这种成形机的基本原理和系统构成,比较了其相对于激光快速成形机的特点与优势,阐述了其应用价值。     

光固化快速成形技术中的精度研究

结合激光快速成形ＬＰＳ－６００Ａ系统论述光固化法快速成形技术中的精度概念，分析影响度的各种因素及改善制件精度的途径，讨论原型制件精度的评价标准问题。     

光固化快速成形中树脂涂层技术研究

分析光固化快速成形对树脂涂层技术的要求及对成形工艺,制件精度,成形效率的影响。并根据液态树脂的物性,分析现有激光快速成形机中各种树脂再涂层方法的特点,提出一种瀑布式树脂再涂层方法。     

快速成形技术的发展

21世纪将是以知识经济和信息社会为特征的时代,制造业面临信息社会中瞬息万变的市场对小批量多品种产品要求的严峻挑战。在制造业日趋国际化的状况下,缩短产品开发周期、减少开发新产品投资风险,成为企业赖以生存的关键。快速成形技术(RP)自80年代问世以来,在成形系统、材料方面有了长足的进步,同时推动了快速制模(RT)和快速制造(RM)的发展,如今快速成形/快速制模/快速制造技术已经成为企业提高竞争力的一种先进手段。     

光固化快速成形中复杂零件型面精度形成机理研究

光固化（ＳＬ）快速原型面型精度（粗糙度、轮廓度等）一直难以提高，分析其形成机理及各种影响因素，结出提高精度的措施，并通过试验进行验证。     

激光快速原型成形法

众所周知,钣金零件的成形加工在大量生产方式下有多种成熟的工艺方法,并在汽车、家电、食品等各种行业中都有广泛应用。但是这些工艺方法都需要设计和制造硬质的工模具,因此需要较长的工艺准备周期和较高的成本。尤其在公差要求严格的情况下,工模具的修改、调整,导致的成本增加和周期延长更不可低估。对于钣金类零件的原型制造以及单件或小批量生产,这些大量生产方式下成熟的工艺方法在一般情况下常常是难以接受的。     

激光快速成形技术的新进展

本文介绍了激光快速成形技术的最新进展，主要包括：金属零件直接成形技术、微纳激光三维成形技术、激光直写三维堆积技术、复合材料光固化成形技术等。作者认为，应当特别关注这些高新技术的应用，以应用来带动其研究，加速发展这些重要的先进成形制造技术。     

激光快速成形加工中扫描方式与成形精度的研究与实验

通过对激光快速成形加工中现有的激光扫描方式进行理论分析和实验验证，找出其生产零件翘曲以及引起其他误差的原因，提出一种扫描方法，解决由树脂收缩引起的零件翘曲和形状误差，并且省去光开关。     

动态优化刮刀速度的新型涂层工艺

为提高活塞式无扰动涂层工艺的涂层质量,针对高分辨率激光快速成形系统涂层工艺中存在的涂层厚度随制件高度增加而变厚的问题,提出在制作过程中动态优化刮刀速度的涂层方法。研究刮刀速度、制件高度对涂层厚度的影响。采用面响应法,建立涂层厚度误差关于制件高度及刮刀速度的数学模型。根据该模型,在制作过程中随制件高度的变化,动态优化刮刀速度,实现涂层厚度均匀化。验证试验结果表明：与普通涂层工艺相比,新型涂层工艺将涂层厚度偏差由27 μm降为6.9 μm,解决了涂层厚度随制件高度增加而变厚的问题,实现涂层厚度的均匀化,提高堆积方向的制作精度。该涂层工艺也可应用于普通光固化激光快速成形系统中,解决制作陷阱结构时涂层厚度随制件高度变厚问题,因此该工艺对于光固化快速成形技术中提高堆积方向制作精度具有重要意义。     

基于光固化法的嵌套器件的工艺研究

简述了合理添加支撑结构的方法,并分析了成型表面粗糙的原因,提出了提高面型精度和避免飘移的多种措施,为嵌套类复杂器件的光固化加工提供了参考。     

Optimization of stereolithography process parameters for part strength using design of experiments

Rapid prototyping (RP) is an emerging technology that has been implemented in many spheres of industry – particularly in the area of new product development. Growth of this field has been rapid in recent years. Stereolithography (SL) is one of the most popular RP process used for rapid tooling applications. There are several process parameters contributing to the strength of an SL product. The contribution of three parameters; namely, layer thickness, post curing time and orientation are most significant. In light of this concern, an attempt has been made to study and optimize these process parameters for maximum part strength, and develop an empirical relationship between process parameters and part strength through design of experiments (DOE). The proposed DOE is verified with the data of experiments conducted under standard conditions.     

Microblasting characteristics of jewellery models built using stereolithography apparatus (SLA)

This paper describes an investigation of the effect of the microblasting process on the surface finish of jewellery models built using stereolithography apparatus (SLA). The layering process of SLA results in visible steps on the model surface. The investigation aims to determine the significant operating parameters of the microblaster deburring process that affect the surface roughness of the SLA jewellery model, to set a practicable range for these parameters for effective deburring and establish the optimum parameters for the best surface finish. A ring model based on the British Standards 28653: 1993 is designed using the Pro-Engineer software. The experimental strategy applies techniques including the full factorial and Yates' method together with the analysis of variance on the deburred samples. The surface roughness of the ring models before and after the deburring process are then measured with a Form Talysurf surface roughness measuring machine. The information obtained is used to identify the parameters for further study. Parameters identified are different nozzle types, blasting time and pressure variation. These parameters are tested for their optimum settings and the microblasting process is found to significantly improve the surface finish by approximately 30% on both the curvature and flat features of the ring model.     

Path planning effect for the accuracy of rapid prototyping system

Stereolithography (SL) is one of the rapid prototyping (RP) systems that use liquid photopolymer resin as the raw material for building prototypes. The photopolymer type of the RP system employs lasers to selectively expose the surface of the liquid resin. The absorbance of energy leads to photo-polymerization that transfers the liquid resin into solid. Subsequently, the phenomenon of volume shrinkage is unavoidable, and the curl distortion changes with the different laser scan paths, even affecting the geometric profile of the final-parts. The volume shrinkage and curl distortion are the major causes that lead to poor accuracy of the built prototype. In order to understand and improve the curl distortion and the geometric profile, so as to find a simple and suitable laser scan path. This paper first of all uses simulation and experiment to explore the deformation and shrinkage during the process of photo-polymerization while the liquid resin uses a laser beam to carry out single line scanning or single layer scanning in liquid free surface, and further understands the final change of geometric profile. Secondly, it investigates into the curl distortion and changes of geometric profile occurred in the three-dimensional part by different scan paths. Finally, a simple, proper, and effective laser scan path planning is suggested to decrease the curl distortion, and promote the dimension accuracy and the profile of the final-parts. Besides, this paper also mentions the feasibility of multi-optical processing.     

光固化零件的变形理论研究

光固化零件的变形是光固化成型工艺中必须解决的关键问题之一。论文主要研究了光固化零件的层内应力—应变分布 ,在推导出相关理论公式的基础上 ,指出减小零件变形的有效措施 :采用对称方式扫描固化可以消除拉弯耦合效应 ;采用正交扫描方式可以消除拉剪耦合效应及弯扭耦合效应 ;减小层厚可减少耦合效应。     

Integrated simulation of the injection molding process with stereolithography molds

Functional parts are needed for design verification testing, field trials, customer evaluation, and production planning. By eliminating multiple steps, the creation of the injection mold directly by a rapid prototyping (RP) process holds the best promise of reducing the time and cost needed to mold low-volume quantities of parts. The potential of this integration of injection molding with RP has been demonstrated many times. What is missing is the fundamental understanding of how the modifications to the mold material and RP manufacturing process impact both the mold design and the injection molding process. In addition, numerical simulation techniques have now become helpful tools of mold designers and process engineers for traditional injection molding. But all current simulation packages for conventional injection molding are no longer applicable to this new type of injection molds, mainly because the property of the mold material changes greatly. In this paper, an integrated approach to accomplish a numerical simulation of injection molding into rapid-prototyped molds is established and a corresponding simulation system is developed. Comparisons with experimental results are employed for verification, which show that the present scheme is well suited to handle RP fabricated stereolithography (SL) molds.