共查询到19条相似文献,搜索用时 171 毫秒
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超音速电弧喷涂粒子速度的计算机仿真 总被引:3,自引:1,他引:2
粒子速度对涂层质量有重要的影响,计算机仿真是确定粒子运动规律的有效方法。通过建立数学模型,对超音速电弧喷涂纯铝的粒子速度进行了仿真计算,结果表明,粒子飞行过程中经历了一个加速减速的过程,直径40μm的粒子最大速度为365m/s,最大速度点离喷嘴出口52mm,试验测得的粒子最大速度为386m/s,位置在喷嘴出口40~60mm范围内。仿真计算反映了射流中粒子的运动特征,从理论上证明超音速电弧喷涂的粒子速度超过音速。 相似文献
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雾化在电弧喷涂中具有重要的作用,滁层质量很大程度上取决于雾化效果。超音速电弧喷涂的雾化过程包括丝材端部的熔化、熔化金属的脱落、熔滴的雾化三个阶段。气流的速度和流量、送丝速度、熔化金属的物理特性、气流的物理特性是影响雾化效果的主要因素。超音速电弧喷涂由于拉伐尔喷咀的作用,雾化效果好,从而得到高质量的涂层。 相似文献
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根据空气动力学和火箭发动机原理,研制了超音速电弧喷涂和多功能超音速火焰喷涂技术,可制备性能优异的耐蚀、耐磨、导电、绝缘涂层.超音速喷涂技术应用于机械零部件的再制造,可显著提高其性能和使用寿命,符合优质、高效、节能、节材、环保的要求,可达到修旧利废的目的,产生良好的经济效益.超音速电弧喷涂可制备金属、合金及基于管状丝材的复合涂层,涂层均匀致密,孔隙率低,结合强度高,在长效防腐、耐磨强化方面有广泛的应用.多功能超音速火焰喷涂技术同时具备HVOF和HVAF的功能,实现了焰流速度和温度大范围内的连续可调,能满足多种材料的喷涂要求,特别是其制备的碳化物陶瓷涂层,综合机械力学性能和耐磨耐蚀性能好,在机械零部件表面强化领域应用广泛. 相似文献
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高速火焰电弧(HVAF-ARC)复合喷涂枪是高速火焰喷涂枪和电弧喷涂枪的结合体,利用产生的高速燃气来雾化加速电弧喷涂过程中产生的熔融粒子,提高了喷涂粒子的飞行速度,降低了粒子的氧化,可高效制备优质的涂层。文中利用自主开发的新型高速火焰电弧复合喷涂枪和普通高速电弧喷涂枪,分别在钢基体上制备了3Cr13涂层,通过对涂层的性能检测发现,复合喷涂枪所制备涂层的氧元素含量和孔隙率都比普通高速电弧喷涂枪制备的涂层低,分别降低了33%和49%,硬度提高了12%,复合喷涂枪制备涂层的性能得到较大的提高。 相似文献
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W. Tillmann E. Vogli M. Abdulgader M. Gurris D. Kuzmin S. Turek 《Journal of Thermal Spray Technology》2008,17(5-6):966-973
To use the manifold possibilities that arc spraying offers to deposit wear resistance layers, knowledge of the particle formation and their behavior is necessary. This work is focused on studying the particle properties during arc spraying with cored wires. Different cored wires under various spraying parameters are investigated by means of a high speed camera. Particle properties in-flight, such as velocity and temperature, are determined. Correlation between particle behavior and particle characteristics at different spraying conditions is established. At the same time, the particle-laden gas flow is simulated numerically and the computed solutions are used to illustrate the utility of the proposed CFD model and compared with experimental results. The employed mathematical model represents a system of macroscopic conservation laws for the continuous gas phase and for the gas-solid mixture. This approach formulation makes it possible to circumvent the numerical difficulties associated with the implementation of a (potentially ill-posed) two-fluid model. The discretization in space is performed using a high-resolution finite element scheme based on algebraic flux correction in terms of local characteristic variables. The artificial diffusion operator is constructed on the discrete level and fitted to the local solution behavior using a multidimensional flux limiter of TVD type. 相似文献
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Wire arc spraying is a coating process in which minor modifications of the configuration and spray parameters can have a strong
impact on coating characteristics. A study on the effects of the fluid dynamics of the atomizing gas on the coating properties
is presented. Different types of nozzles, shrouds, and gases have been used to provide various flow velocities and reactive
environments in the metal atomization region. The effects on particle velocity, coating density, composition, and interface
characteristics between the coating and the substrate have been evaluated. It is clear that higher gas velocities improve
practically all coating properties, but also increase oxide content in the coating. However, the oxidation can be drastically
reduced if nonoxidizing gases are used for atomization in combination with a shroud. A discussion on the physical effects
contributing to the observed adhesion improvements and interfacial properties is provided. 相似文献
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在G型喷嘴下,利用SprayWatch-2i喷涂粒子速度、温度测试仪在线测量粒子的飞行参数,研究了等离子喷涂工艺参数对喷涂粒子速度和温度的影响,并对等离子喷涂氧化锆粉末的主要工艺参数进行优化分析。在诸因素中.气体流量对粒子速度和温度的影响最为显著,随着主气流量的增加,粒子速度有所增加。 相似文献
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Difference in particle characteristics and coating properties between spraying metallic and ceramic powder cored wires 总被引:2,自引:0,他引:2
The sprayed particles of metallic and cermet wires were collected to analyze the atomization state of the particles in arc spraying forming, the microstructure and properties of metallic and ceramic coatings were investigated and compared. Particle size analyzer was used for quantifying particle size. The XRD, SEM and optical microscope(OM) were used to analyze the phase composition and microstructure of the particles and coatings. From the experimental results, some difference of particle characteristics was established between the spraying metallic and ceramic cored wires, and the microstructure and properties of coatings depend strongly on the particles behaviors. The result shows that Fe-TiB2/Al2O3 composite coating has a high potential for abrasive wear applications. 相似文献