• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2017, Vol. 53 ›› Issue (24): 1-11.doi: 10.3901/JME.2017.24.001

• 特邀专栏:表面工程先进技术及其服役行为(上) •    下一篇

等离子射流与喷涂粒子微观交互作用研究现状

王海斗, 陈书赢, 马国政, 邢志国, 何鹏飞, 徐滨士   

  1. 装甲兵工程学院装备再制造技术国防科技重点实验室 北京 100072
  • 收稿日期:2017-05-15 修回日期:2017-09-21 出版日期:2017-12-20 发布日期:2017-12-20
  • 通讯作者: 马国政(通信作者),男,1984年出生,博士,助理研究员,硕士研究生导师。主要研究方向为再制造、表面工程、空间摩擦学。E-mail:magz0929@163.com
  • 作者简介:王海斗,男,1969年出生,博士,研究员,博士研究生导师。主要研究方向为再制造、表面工程、装备摩擦学。E-mail:wanghaidou@aliyun.com;陈书赢,男,1990年出生,博士研究生。主要研究方向为热喷涂、表面工程。E-mail:chenshuying90@163.com
  • 基金资助:
    国家自然科学基金(51675531,51535011)和北京市自然科学基金(3172038)资助项目。

Research on the Micro Interaction of Plasma Jet and Spraying Particles: A Review

WANG Haidou, CHEN Shuying, MA Guozheng, XING Zhiguo, HE Pengfei, XU Binshi   

  1. National Key Lab for Remanufacturing, Academy of Armored Forces Engineering, Beijing 100072
  • Received:2017-05-15 Revised:2017-09-21 Online:2017-12-20 Published:2017-12-20

摘要: 从微观角度看,等离子喷涂层实质上是由大量喷涂粒子在等离子射流中经过一系列复杂的理化变换之后,撞击基体并迅速铺展凝固所形成的,因而熔滴撞击基体前的理化特性对涂层的组织结构、缺陷密度、力学性能等指标具有重要影响。通过对喷涂粒子基本特征参数、射流中的传热机理、传质机理与粒子加速行为四个方面的总结,详细综述等离子射流与喷涂粒子的交互作用过程。总体来说,温度、速度是粒子的基本特征参数,而采用一些综合温度与速度的复合参数(如熔融指数、雷诺数、韦伯数等)对熔滴的理化特性具有更好的表征效果;粒子的加热过程由表及里,受到热导率、比表面积、热容量、飞行路径及射流特性等多种因素影响,部分熔滴容易由于温度过高而发生汽化现象;处于熔融状态的粒子具有较高的活性,因而容易在射流中与气体介质发生反应,包括O2、N2、H2等,同时粉体内部也会发生一定的元素迁移或化学反应;粒子在射流中由于受到气流拖拽力、重力、热泳力及气压梯度力的综合作用而不断加速,同时会由于射流特性及熔化状态的差异而发生不同程度的破碎或细化现象。

关键词: 传热传质, 等离子喷涂, 交互作用, 喷涂粒子

Abstract: Microscopically, plasma sprayed coating is essentially fabricated by a stream of particles which experience a series of complicated physicochemical transformations in plasma jet and undergo rapid spreading and solidification after impacting the substrate. Therefore, the deposition quality of the droplet before impinging on the substrate has an important influence on the microstructure, defect and mechanical properties of the coating. The detail process of the interaction between plasma jet and particles is introduced in four aspects, namely, the basic parameters, the mechanism of the heat, mass and momentum transfer. The results indicate that the temperature and the velocity are the basic characteristic parameters of the particles, while the synthetic parameters of the temperature and velocity are proved to be more suitable to characterize the deposition quality of the droplets; the particles are heated from surface to interior and some of the droplets are prone to vaporize due to high melting status, which are effected by thermal coefficient, specific surface area, heat capacity, injection path, jet characteristics and so on; the molten droplets is easily to react with the atmosphere, i.e. O2, N2 and H2, due to high chemical activity, which can lead to the element migration and chemical reaction in the powder; the particles injected into the plasma jet are accelerated by the drag force, gravity, thermophoretic force and pressure gradient force, which can resulting in different degrees of fragmentation or refinement of the particles owing to the characteristics of the plasma jet and the molten state of the droplets.

Key words: heat and mass transfer, interaction, plasma spray, spraying particles

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