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一方面,激光束作为一种高能量密度的热源,由于其潜的优势,使其在焊接领域得到了迅速的发展和应用,已逐渐成为传统焊接技术的补充和发展,对其工艺方法的深入研究可为其在国内的应用建立良好的基础;另一方面,焊接过程是一个高度非线性、多变量耦合,同时具有大量随机不确定因素的复杂过程,而人工神经网络(ANN)由于其具有非线性映射及自学习等特点,使其在焊接领域的研究中与传统方法相比具有一定优势。本文通过对YAG激光深熔焊试验的正交设计和对试验数据的分析,采用人工神经网络的方法,建立网络模型,并且基于MATLAB软件,编程实现了YAG激光深熔焊的熔深预测和针对不同熔深要求对主要工艺参数的预测。 相似文献
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In the special processes field, where welding processes are historically among the most significant examples, laser welding and cutting are certainly among the technologies that stand out the most due to their innovative content and potential for industrial applications, also when considered in synergy with conventional arc welding processes, such as MIG welding, for example. On the other hand, they are clearly distinguished from arc welding processes due to their technological specificity, particularly with reference to the methods adopted for personnel and process qualification. The fundamental aim of this paper is to analyse the state-of-the art in relation to standardization activities, with particular reference to the qualification of personnel and processes in accordance with European standards. 相似文献
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激光熔覆制造致密金属零件送料方式的分析和比较 总被引:2,自引:0,他引:2
分析比较了激光熔覆直接成形技术中的送料方式及装置,在对铺粉、送粉、送丝3种主要送料方式进行总结、比较的基础上,认为送丝法具有独特优点,有必要对其做更深入的研究。 相似文献
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冲刷腐蚀广泛发生在石油、化工等领域,并致使设备材料发生损伤或失效。材料经激光熔覆后得到具有特殊化学、力学性能,并能与基体材料形成冶金结合的涂层。从激光熔覆层冲刷腐蚀行为研究方法出发,简要概括了现场测试法、数值模拟法以及通过模拟真实工况进行实验室研究的三大类实验装置的优缺点,并对目前用于激光熔覆层冲刷腐蚀行为的表征方法进行了总结。然后介绍了激光熔覆层冲刷腐蚀机理的研究现状:冲刷腐蚀机制由电化学腐蚀、机械力磨损及二者交互作用构成,其中冲刷主要通过正应力和切应力两种侵蚀机制对腐蚀产生促进作用,而腐蚀则通过弱化涂层表面促进冲刷。随后,总结了激光熔覆层冲刷腐蚀行为的影响因素,并对熔覆材料自身因素、流体因素(流速、冲蚀角、固体颗粒及pH值、温度等)对激光熔覆层冲刷腐蚀行为的影响规律进行了分析和归纳。最后,基于冲刷腐蚀机理研究现状,从研究方法及影响因素等方面总结了目前激光熔覆层冲刷腐蚀研究中存在的问题,同时对未来的研究趋势进行了展望。 相似文献
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为了在竞争中获胜,欧洲造船业必须提高生产速度和效率,同时降低成本。因此,他们投入了巨大的人力和财力来研发激光焊接并将其应用到造船生产实践中,以达到维持和重建欧洲船厂在全球高附加值船舶市场的优势地位。 相似文献
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航空铝合金材料的两种表面激光冲击加工技术的比较 总被引:8,自引:4,他引:8
简要介绍了航空金属材料的激光冲击强化技术和激光冲击成形技术,并从工艺参数、力学效应以及应用效能等方面进行了比较。铝合金材料经过激光加工处理后,能显著增加航空器关键零部件的表面残余压应力,提高疲劳抗力。此技术可应用到特殊材料的小曲率弯曲成形,很好地适应宇航工业的生产要求。 相似文献
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目前焊缝表面检测主要依靠肉眼观察和简单测量实现,其科学性、精确性受到检验人员主观因素的影响。线激光扫描方法是工业应用中比较先进的非接触轮廓检测方法。通过线激光扫描,利用激光三角测量法可以得到物体轮廓,进而得到物体的形貌信息。基于上述技术,开发了一套焊缝轮廓线激光检测系统,系统由半导体线激光器、CMOS工业相机、LabVIEW虚拟仪器软件平台组成。基于LabVIEW编写了包括图像采集、图像处理与焊缝轮廓计算的系统,能够得到较为准确的焊缝表面轮廓信息。 相似文献
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Characterization of modified thick thermal barrier coatings 总被引:1,自引:0,他引:1
Ahmaniemi S. Tuominen J. Vippola M. Vuoristo P. Mäntylä T. Cernuschi F. Gualco C. Bonadei A. Di Maggio R. Ahmaniemi S. 《Journal of Thermal Spray Technology》2004,13(3):361-369
In gas turbines and diesel engines, there is a demand for thick thermal barrier coatings (TTBCs) due to the increased process
combustion temperatures. Unfortunately, the increased thickness of plasma-sprayed thermal barrier coatings (TBCs) normally
leads to a reduced coating lifetime. For that reason, the coating structures have to be modified. When modifying the structure
of TTBCs, the focus is normally on elastic modulus reduction of the thick coating to improve the coating strain tolerance.
On the other hand, coating structural modification procedures, such as sealing treatments, can be performed when increased
hot-corrosion resistance or better mechanical properties are needed. In this article, several modified zirconia-based TTBC
structures with specific microstructural properties are discussed. Coating surface sealing procedures such as phosphate sealing,
laser glazing, and sol-gel impregnation were studied as potential methods for increasing the hot-corrosion and erosion resistance
of TTBCs. Some microstructural modifications also were made by introducing segmentation cracks into the coating structures
by laser glazing and by using special spraying parameters. These last two methods were studied to increase the strain tolerance
of TTBCs. The coating microstructures were characterized by optical microscopy, a scanning electron microscopy (SEM), transmission
electron microscopy (TEM), energy dispersive spectroscopy (EDS), and x-ray diffraction (XRD). The effect of sealing procedures
on the basic thermal and mechanical properties of the coatings was studied. In addition, some correlations between the coating
properties and microstructures are also presented, and the advantages and drawbacks of each modification procedure are discussed. 相似文献
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随着对汽车安全性能要求的日益提高,车顶的连接强度也越来越受到重视,尤其是当汽车发生碰撞而颠覆时,车顶的连接强度将直接影响车内乘务人员生命安全.车顶和侧围的连接也一直是白车身制造中的关键连接技术之一,着重介绍几种现有的车顶与侧围连接方式,如电阻点焊、激光焊接、激光钎焊、等离子钎焊、复合连接等,分别介绍它们成本、工艺、技术... 相似文献
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铝及其合金在汽车工业的应用中具有轻量化、节能减排、改善环境、提高汽车平稳性和安全性等特点。铝及其合金熔化焊存在焊缝易产生气孔,焊接接头易软化等缺陷。讨论了激光-电弧复合焊、激光拼焊、搅拌摩擦焊在汽车用铝及其合金焊接的应用和特点。 相似文献
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在相同的激光工艺参数条件下,对经调质,离子渗N、离子NC共渗和稀土催渗NC共渗的42CrMo钢进行相变复合处理,试验结果表明,离子NC共渗和稀土催渗NC共渗渗速度快,渗层深度大,渗层和钢表面的碳浓度高,使Ms点降低,增加了复合处理的硬化层深度,提高了硬化层的硬度,硬化层组织不高于其它复合处理,在滑动磨粒磨损条件下,其耐磨性比其它复合处理的更好。 相似文献