基于激光熔覆的快速制造技术的初步研究

【作者】 王建军；

【导师】 杨洗陈； 王云山；

【作者基本信息】 天津工业大学 ， 机械制造及其自动化， 2003， 硕士

【摘要】 基于激光熔覆的快速制造技术(LCRM)是一项近几年才兴起的快速成形技术，它是激光熔覆理论和快速成形技术的集成。它通过激光熔化同轴送粉咀输送的金属粉末，在基材上逐层熔化堆积而形成金属零件。和传统的制造方法相比，该项技术具有几个突出的优点：生产成本低、周期短、市场响应快，并且制造的零件具有优越的综合性能，还可以利用不同材料制造具有梯度功能的零件等。该技术作为一项非常有应用前景先进制造技术，已经受到越来越广泛的关注。 本文以激光熔覆理论和快速成形技术为基础，对基于激光熔覆的快速制造技术进行了初步研究。论文的主要内容如下：首先分析了在非载气同轴送粉情况下粉末流的密度分布、粉末颗粒的吸热特性以及粉末流对激光束的衰减规律，并在此基础上建立了激光能量在粉流中透过率的数学模型。然后利用相关理论和机械设计知识，设计了结构简单实用四路分粉器，以及一种新型非载气式同轴送粉咀。接着针对非载气同轴送粉咀进行了一系列试验，包括：同轴送粉咀性能测试，各工艺参数对粉末利用率、单道熔覆层宏观质量以及多层熔覆层宏观质量(如：熔覆层的表面质量、硬度分布、开裂现象等)的影响，并分析了多层熔覆层的微观组织和成分分布。在上述试验的基础上确定了合适工艺参数范围。另外还针对LCRM技术开发了专用的CAD／CAM软件，该软件是对AutoCAD的二次开发，开发工具为ObjeARX，主要由实体造型模块、分层及截面数据处理模块、NC代码生成模块、加工轨迹模拟模块以及数据传输模块组成。最后制造出了简单的金属零件(矩形零件、叶片、螺杆)。更多还原

【Abstract】 Laser Cladding Rapid Manufacturing (LCRM) is a new rapid shaping technology, which is the integration of laser cladding theory and rapid shaping technology. It uses laser beam to melt metallic powder fed by co-axial nozzle layer by layer on a substrate, then a solid and functional component is produced. Comparing with traditional manufacturing method, it has some special advantages: low produce cost, short produce time, rapid response to market, component having excellent mechanical properties and graded function with variable composition and so on. It has been given more and more attention, as an advanced manufacturing technology having great potential.In this paper, LCRM is primary researched. The research mainly includes four parts. Firstly, aiming at the co-axial feeding powder, on the basis of the analysis of the density distributing of powder stream, the absorbency of metallic particle and the attenuation of laser beam by powder stream, the equation of laser power permeation rate is established in powder stream. Secondly, according correlative theory and machine design knowledge, a simple and applied four-road powder splitter and a novel co-axial nozzle without carrying gas are designed. Thirdly, a serial experiments are done, including: testing the co-axial nozzle performance, studying the effect how processing parameters affect cathment efficiency of powder, macroscopical quality of single-layer cladding and macroscopical quality of multi-layer cladding (surface quality, rigidity, crack etc.), and analyzing the microcosmical organization and the distributing of composition. Then, on the basis of above experiments, the right processing parameters is ascertained and metallic components are produced, such as complicated rectangle component and vane. Finally, a special CAD/CAM soft is developed used in LCRM, through developing AutoCAD application using ObjectARX. It is mainly consisted of generating solid module, cutting and acquiring interface data module, generating NC code module, simulating processing track and transmitting data module.更多还原