冷喷涂技术应用现状与展望

冷喷涂是近几年来发展起来的新型表面涂层技术,由于冷喷涂技术是在较低的温度下进行的,与其他方法制备的涂层相比具有很多的优势。本文从冷喷涂技术概述和冷喷涂技术应用现状与展望两方面对冷喷涂技术进行了论述,希望对国内外冷喷涂技术应用现状有所了解。     

冷喷涂技术的研究进展与应用

近年来,冷喷涂技术是一门备受关注的新兴技术,冷喷涂过程中超音速金属粒子以固态形式碰撞基体后产生剧烈的塑性变形从而形成沉积。 由于冷喷涂的沉积可以实现连续堆积而逐层增厚,从而使该技术从一种涂层加工技术发展成为一种快速的增材制造技术。 经历了 30 多年的迅猛发展,冷喷涂技术的研究方向正在从基础理论研究转变到应用开发,其中一些应用已经实现工业化量产。 文中介绍了冷喷涂的技术及工程化应用特点,展示了典型冷喷涂涂层性能等基础研究以及冷喷涂涂层应用等开发方面的工作,并且重点介绍了冷喷涂技术在航空航天、能源动力、电子电力、增材制造等领域的应用研究方面所取得的一些新进展。     

冷喷涂技术

冷喷涂技术是近年来发展迅速的工业表面喷涂新技术.本文介绍了冷喷涂技术的原理、系统构成与冷喷涂的特点,以及影响冷喷涂主要工艺参数、粒子沉积行为与涂层性能等研究现状.并结合国内外的发展现状对冷喷涂技术的应用前景进行了展望.     

冷喷涂技术

冷喷涂技术是近年来发展迅速的工业表面喷涂新技术。本文介绍了冷喷涂技术的原理、系统构成与冷喷涂的特点,以及影响冷喷涂主要工艺参数、粒子沉积行为与涂层性能等研究现状。并结合国内外的发展现状对冷喷涂技术的应用前景进行了展望。     

冷喷涂在焊接工程中的应用与展望

冷喷涂是基于空气动力学与高速碰撞动力学原理的喷涂技术,它是一种新型涂层制备技术,是目前国际热喷涂领域的研究前沿.简要介绍了冷喷涂技术的原理与主要特点,以及冷喷涂技术的主要应用研究现状.根据冷喷涂技术独特的优点,如涂层含氧量低、可将喷涂材料的组织结构在不发生变化的条件下转移到基体表面等.对冷喷涂技术在焊接制造领域内的应用前景进行了展望.冷喷涂能够应用于钎焊、扩散焊、材料的自由连接以及改善焊接接头的疲劳性能等焊接工程.     

冷喷涂设备及冷喷涂技术应用研究进展

冷喷涂技术相比于传统热喷涂技术有许多优势,例如喷涂温度低,涂层氧含量低,孔隙率低,在喷涂过程中不易发生氧化、烧损、相变等现象,这使得传统喷涂技术难以制备的氧敏感、热敏感、非晶、纳米材料涂层成为可能。从冷喷涂技术原理出发,介绍了各类冷喷涂设备及冷喷涂涂层的沉积机理,详细阐述了冷喷涂涂层结合机理和结合方式(机械咬合、物理结合、冶金结合、化学结合),介绍了各类冷喷涂装备(高压和低压冷喷涂系统、真空冷喷涂系统、激光辅助冷喷涂系统、静电辅助冷喷涂系统、脉冲气体冷喷涂系统和激波风洞冷喷涂系统)及其研究现状。综述了近几年冷喷涂技术在防腐涂层、耐磨涂层、生物医用、抗菌涂层、电子工业、功能涂层、修复与再制造等领域的研究和应用现状,最后对冷喷涂技术的应用和发展前景进行了展望。     

冷喷涂技术在铜质螺旋桨维修中的应用研究

总结了铜质螺旋桨常见的失效形式机及其带来的不良影响;介绍了修复铜质螺旋桨的传统工艺方法、该方法的利弊和适用范围;提出了冷喷涂工艺修复铜质螺旋桨,综述了冷喷涂工艺的基本原理及其研究现状,并对冷喷涂工艺修复铜质螺旋桨进行可行性分析。分析了运用冷喷涂技术进行维修的可行性和独特优势,并对冷喷涂技术在快速修复领域的应用前景进行展望。总结得出:研制更加便携高效的冷喷涂修复装置是未来发展的前沿方向之一。     

冷喷涂技术的最新进展及应用研究

冷喷涂技术是近几年发展起来的新型喷涂工艺,低压冷喷涂是基于原冷喷涂技术上的一种改进,它与高压冷喷涂一样是冷喷涂技术的最常见的两个分支.通过对低压冷喷涂与原冷喷涂技术的工艺差别的比较,从技术原理、涂层的制备和性能分析的角度,分析这种新型的低压喷涂技术的应用前景.     

冷喷涂技术的研究进展

冷喷涂是基于空气动力学原理的一种新型喷涂技术.它是利用低温(一般低于600℃)超音速气体射流加速喷涂粒子,使粒子不熔化,以固态形式与基体发生塑性碰撞而实现涂层沉积.相比于热喷涂技术,冷喷涂可以避免材料在喷涂过程中发生过热、氧化、晶粒长大等现象,适用于非晶、纳米晶涂层的制备.介绍了冷喷涂技术的原理、特点、沉积机制和工艺参数,总结了冷喷涂纳米涂层的研究进展.     

真空冷喷涂技术及其在功能器件中的应用

真空冷喷涂作为一种有潜力的新型涂层制备工艺,已引起来自多个国家研究团队的关注。 超细陶瓷或金属颗粒以数百米每秒或更高速度撞击基体与累加沉积,无需高温烧结,即可在室温下制备致密或多孔的纳米结构陶瓷涂层或金属涂层。 该工艺具有材料适用广泛、成分不易发生变化、可直接快速制备复合材料以及多种结构涂层的优势。 尤其是在功能陶瓷领域,真空冷喷涂有希望成为以烧结为基础的传统生产工艺的替代品。 文中详细阐述了真空冷喷涂工艺的原理与特点、颗粒沉积行为和典型涂层形貌,并介绍了真空冷喷涂工艺在传感器( 气体、湿度和温度) 、能源器件(太阳能电池、燃料电池、锂离子电池和超级电容器等) 、微机电系统( MEMS) 器件、表面防护、生物涂层以及金属涂层等领域的应用和最新研究进展。 最后对真空冷喷涂工艺的未来研究方向和应用领域进行了展望。     

冷喷涂特性

冷喷涂技术是近年来发展起来的新型喷涂技术，该方法通过低温（＜600℃）的高速固态粒子与基体发生塑性碰撞而实现涂层沉积，可以避免喷涂材料在喷涂过程中受热影响而发生氧化，分解等，可以将喷涂材料的组织结构在不发生变化的条件下移植到基体表面，简要介绍了冷喷涂技术的原理与特点，冷喷涂层的组织结构与性能以及涂层沉积特性与行为的研究现状，粒子的速度对于涂层的沉积起着决定性作用，对于一定的材料存在一临界速度，约为500－600m/s，当粒子速度超过该临界速度后，随着速度的增加，沉积效率增加，最高可以达到80％以上，迄今的研究表明，冷喷涂可以实现大多数金属材料甚至金属陶瓷材料的沉积。     

Rare Earth/Metal Composite Formation by Cold Spray

Nd₂Fe₁₄B permanent magnet/aluminum composite coatings were produced by cold spray deposition. Isotropic Nd₂Fe₁₄B powder was blended with aluminum powder to make mixtures of 20-80 vol.% Nd₂Fe₁₄B, and these mixtures were sprayed at temperatures of 200-480 °C. The hard Nd₂Fe₁₄B particles tended to fracture and fragment upon impact, while aluminum underwent severe plastic deformation, eliminating pores, and trapping Nd₂Fe₁₄B within the coating. It was found that higher spray temperatures and finer Nd₂Fe₁₄B particle sizes improved the retention rate of Nd₂Fe₁₄B within the composite structure. This was explained from a contact mechanics viewpoint by calculating the effect of process parameters on the rebound momentum of Nd₂Fe₁₄B particles. The magnetic properties of Nd₂Fe₁₄B remained unaffected by the cold spray process.     

低压冷喷涂增材制造铜基块体性能研究

采用低压冷喷涂增材制造技术制备铜基块体材料,测试块体材料导热性能及力学性能,利用场发射扫描电镜对块体材料截面、拉伸断面进行观察与分析。结果表明,Al_2O_3体积比为10%的铜基粉末制备的铜基块体材料的导热性能较好,随着Al_2O_3含量的增加,铜基块体材料导热性能下降。冷喷涂铜基块体材料经退火处理后,导热性能及力学性能有所提升。随着退火温度的上升,热扩散率及抗拉强度呈现先上升后下降的趋势,在退火温度为500℃时,热处理态铜基块体材料热扩散率为加工态铜块体材料的80.43%,抗拉强度为125.3 MPa。     

Characterization of Cold Spray Titanium Supersonic Jet

Titanium is widely used in aerospace, highly corrosive environments, and implants due to unique properties such as high strength to weight ratio and excellent corrosion resistance. Cold gas dynamic spray (cold spray) technology, in contrast to current fabrication technologies, has provided the potential for titanium to be utilized in broader industrial applications and at lower cost. Particle velocity is the most important parameter in the cold spray process that leads to successful deposition of titanium at supersonic speeds. In this study, particle image velocimetry (PIV) is utilized to characterize supersonic flow field for a commercially pure (CP) titanium powder. The results represent experimentally determined velocity for titanium particles under supersonic conditions with respect to propellant gas, spray temperature, and stagnation pressure. The high velocity flow region outside of the cold spray nozzle was significantly extended using helium. An increase in stagnation temperature results in a high velocity region close to the axis of the cold spray nozzle. In contrast, an increase in pressure expands the high velocity regions in the cold spray plume. The PIV that is a whole-flow-field process is a practical characterization technique for optimization of parameters and validation of the future models for the cold spray process.     

A Three-Dimensional Analysis of the Cold Spray Process: The Effects of Substrate Location and Shape

A three-dimensional model of a Cold Gas Dynamic Spray system with a peripheral nonaxisymmetric powder feeder is studied in this work. It is found that the stagnation pressure alternates for different substrate standoff distances due to the nature of the supersonic flow interaction with the substrate. One can find the optimum substrate location for any given operating condition, which results in minimum pressure buildup on the substrate. The three-dimensional analysis sheds more light on the complex gas and particle flow fields generated due to the three-dimensional particle injection process. In addition, the three-dimensional model allows us to further investigate the effect of practical substrate shapes (such as convex and concave) on the flow field and consequently to determine the optimum conditions to deposit coating particles. This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain Montavon, Ed., ASM International, Materials Park, OH, 2007.     

Investigation of Al-Al2O3 Cold Spray Coating Formation and Properties

Coating build-up mechanisms and properties of cold-sprayed aluminum-alumina cermets were investigated using two spherical aluminum powders having average diameters of 36 and 81 μm. Those powders were blended with alumina at several concentrations. Coatings were produced using a commercial low-pressure cold spray system. Powders and coatings were characterized by electronic microscopy and microhardness measurements. In-flight particle velocities were monitored for all powders. The deposition efficiency was measured for all experimental conditions. Coating performance and properties were investigated by performing bond strength test, abrasion test, and corrosion tests, namely, salt spray and alternated immersion in saltwater tests. These coating properties were correlated to the alumina fraction either in the starting powder or in the coating. This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain Montavon, Ed., ASM International, Materials Park, OH, 2007.     

Numerical Study of Combination Parameters for Particle Impact Velocity and Temperature in Cold Spray

Numerical simulations of gas/particle flows of cold spray are performed for N₂ and He, respectively, to investigate the usefulness of the two material-independent combination parameters derived from the equations of particle motion and temperature. The first combination parameter is the particle-diameter multiplied by the material density, which governs the particle velocity. The second one is the squared particle-diameter multiplied by the material density and specific heat, which affects the particle temperature. In the numerical simulation, the materials of the spray particle selected are WC-12Co, Cu and Ti. The numerical results show that the maximum impact velocity of particle is obtained, when the first combination parameter takes specific value regardless of the material type. Furthermore, it is shown that the particle diameter and its temperature corresponding to the maximum impact velocity can be graphically estimated by using the two combination parameters for any powder-materials normally used for the thermal spray. This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain Montavon, Ed., ASM International, Materials Park, OH, 2007.     

冷喷涂沉积机理及其装备的研究进展

冷喷涂是近几年基于空气动力学发展起来的新型表面改性技术。冷喷涂技术在较低的温度下进行,相比热喷涂有很多优势,成为研制开发非晶、纳米及其他温度敏感材料的有效手段,在工业及国防领域有着重要的应用前景和价值。简要介绍了冷喷涂技术的原理、特点以及在保护涂层、功能涂层、近净成形、零件修复等方面的应用。涂层沉积机理的研究对冷喷涂技术的研究具有重要的理论意义,对工艺参数的优化以及优质涂层的制备具有重要的指导作用。冷喷涂装备对涂层质量和喷涂效率的提高至关重要。冷喷涂装备使冷喷涂技术的研究从理论研究到实验研究过渡,最终由实验室研究向工业应用过渡。详细阐述了冷喷涂涂层沉积机理及其研究进展。系统阐述了冷喷涂装备(真空冷喷涂、激光辅助冷喷涂、脉冲气体冷喷涂、激波风洞冷喷涂等)的工作原理及研究现状。     

冷喷涂技术及其系统的研究现状与展望

与传统的热喷涂相比,冷喷涂具有沉积温度低、沉积效率高、孔隙率低,以及粉末在沉积过程中不易发生氧化、分解、相变和纳米结构材料的晶粒长大等问题,这使得氧化敏感、温度敏感和相变敏感等材料的高质量涂层制备成为可能.更值得一提地是,近年来冷喷涂工艺与设备的大力发展使冷喷涂作为一种快速固态成形工艺,在金属增材制造和航空航天等关键零...     

不锈钢表面冷喷涂铜涂层组织和性能研究

采用冷喷涂技术在不锈钢表面喷涂纯铜涂层;涂层的断面形貌和硬度分别通过光学金相显微镜观察和显微硬度计测试,同时研究了涂层的结合机理.结果表明,粉末在沉积过程中存在低速粒子,部分低速粒子沿原路径反弹后影响其他粒子的沉积;纯铜涂层与基体的结合为机械结合;涂层内部兼有部分冶金结合;涂层的硬度分布较均匀,且高于纯铜的硬度.