金属选区激光熔化3D打印关键技术研究

发布时间：2018-03-21 06:21

本文选题：选区激光熔化成型　切入点：结构组成　出处：《南京航空航天大学》2017年硕士论文　论文类型：学位论文

【摘要】：选区激光熔化成型作为近几年受到极高关注度的一门热点技术,正在被越来越广泛地运用于航空航天精密零件、生物医疗等机械制造领域。如果这一技术能够在原有基础上不断进步,将会对制造业的发展起到巨大的推动作用。本文以选区激光熔化成型技术作为对象,从设备结构、关键工艺技术、扫描路径算法等3个方面进行了研究,主要内容如下:(1)针对选区激光熔化成型设备的结构组成,从几大关键系统入手对其进行了分析与设计。根据激光光路系统中激光特征参数和激光扩束的理论分析,比较两种不同振镜扫描聚焦系统的数学模型优缺点,分析振镜镜片旋转角度和扫描点坐标位置之间的关系。自行设计了铺粉系统中成型仓的仓内结构,包括工作台、铺粉系统、刮刀、成型缸。对不同送粉装置和刮粉装置进行优缺点对比,探讨了辅助系统在零件成型质量方面的关键作用。(2)针对选区激光熔化成型过程中振镜延时对表面成型过程的影响,分析了产生这类问题的原因,并对其进行了理论分析。利用ANSYS软件建立模型并进行了有限元模拟仿真,得到温度场与应力场分布云图,设计实验对仿真结果进行验证。(3)根据选区激光熔化成型中的扫描过程,编写了一套路径规划方法。将轮廓层信息文件数据读取,实现三维模型的重现。对层信息中的冗余数据进行清理,对内外轮廓进行缩放来补偿激光光斑直径产生的影响,通过扫描线与轮廓求交得到扫描点坐标,对这些点数据进行排序处理,并保存入数组中得到最终扫描点控制坐标。开发了一款能够实现扫描路径自动生成软件,对主要人机交互界面进行设计。本文对选区激光熔化成型关键技术的研究有一定的分析成果,而且通过实验验证,能够有效提高整个制造过程的加工质量,可以得到较好表面的成型零件,为国内该领域的研究提供了技术经验。
[Abstract]:As a hot technology with high attention in recent years, selective laser melting molding is being more and more widely used in aerospace precision parts. Biomedicine and other fields of mechanical manufacturing. If this technology can continue to progress on the basis of the original, it will play a great role in promoting the development of the manufacturing industry. In this paper, selected laser melting molding technology as the object, from the equipment structure, The key technology, scanning path algorithm and other three aspects are studied. The main contents are as follows: (1) aiming at the structure composition of selective laser melting molding equipment, Based on the analysis of laser characteristic parameters and the theoretical analysis of laser beam expansion, the advantages and disadvantages of two kinds of mathematical models for scanning and focusing system with different vibroscope are compared. The relationship between the rotation angle of the mirror lens and the coordinate position of the scanning point is analyzed. The in-bin structure of the forming bin in the powder laying system is designed, including the worktable, the powder laying system, the scraper, The advantages and disadvantages of different powder feeding and scraping devices are compared, and the key role of auxiliary system in forming quality of parts is discussed. Aiming at the influence of vibrating mirror delay on the surface forming process during selective laser melting molding, In this paper, the causes of this kind of problems are analyzed, and the theoretical analysis is carried out. By using ANSYS software, the model is established and the finite element simulation is carried out, and the distribution of temperature field and stress field is obtained. According to the scanning process of selective laser melting molding, a set of path planning method is developed to read the profile information file data. The redundant data in the layer information is cleaned up and the inside and outside contour is scaled to compensate for the influence of laser spot diameter. The scanning point coordinate is obtained by intersecting the scanning line and contour. The data of these points are sorted and stored in the array to get the final scanning point control coordinates. A software is developed to automatically generate the scanning path. The main man-machine interface is designed. In this paper, the key technologies of selective laser melting molding are analyzed, and the experimental results show that the machining quality of the whole manufacturing process can be improved effectively. Good surface forming parts can be obtained, which provides technical experience for domestic research in this field.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG665

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