| 摘要: |
| 为了探究等离子喷涂制备ZrB2-SiC涂层组织结构疏松、致密性差的原因，采用去离子水对经过射流场加热的粉体进行收集，对比前后粉体的组织结构特征以及物相变化。设计单颗粒沉积试验探究粉体的熔化状态以及变形颗粒的形貌特征，并与等离子喷涂制备涂层进行对应分析。结果表明，由于“涡流效应”使得经过等离子射流场的ZrB2-SiC粉体与卷入的氧气发生反应，粉体出现轻微氧化现象。经过等离子射流场后，ZrB2-SiC粉体呈现3种形貌特征：表面光滑型、表面多孔型、表面团聚型。其原因与等离子射流温度场非均匀性以及粉体的飞行路径有关。变形颗粒呈现与之相对应的3种形貌特征：熔化充分颗粒、团聚堆积颗粒、以及介于两者间的半熔融半疏松颗粒。共晶组织包裹的ZrB2颗粒容易在涂层中形成致密区，而团聚堆积的ZrB2和SiC颗粒是涂层形成疏松区的主要原因。 |
| 关键词: ZrB2-SiC 等离子喷涂 单颗粒沉积 微观形貌 致密度 |
| DOI：10.11933/j.issn.1007-9289.20190624003 |
| 分类号:TG174.442 |
| 基金项目:国家自然科学基金（51772027） |
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| Interaction Between ZrB2-SiC Powder and Plasma Jet Field |
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SUN Shijie1, LIU Yanbo1, MA Zhuang1, XU Junjie1, GUO Jiayi2
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1.National Key Laboratory of Science and Technology on Materials under Shock and Impact, Beijing Institute of Technology, Beijing 100081, China;2.Beijing Xinghang Electro-mechanical Equipment Co., Ltd., Beijing 100074, China
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| Abstract: |
| In order to explore the reasons of loose structure and poor density of ZrB2-SiC coating prepared by APS, the ZrB2-SiC powder flying away from the jet field were collected by deionized water, and the microstructure and phase change of the powders before and after the plasma spheroidization were compared. The single particle deposition experiment was designed to investigate the melting state of the powders and the morphologies of the deformed particles, and the microstructure of the corresponding ZrB2-SiC coating were detected combining with previous powder results. The results show that the ZrB2-SiC powder in the plasma jet field reacts with the entrapped oxygen due to the “vortex effect”, and the powder exhibits slight oxidation. The ZrB2-SiC powder exhibits three morphological features: smooth surface, porous surface, and agglomerated surface after plasma spheroidization. The reasons are related to the unevenness temperature field of the plasma jet field and the flight paths of the powder. The deformed particles exhibit corresponding three topographical features: melted sufficient particles, agglomerated stacked particles, and semi-molten and semi-loose particles. The eutectic tends to form dense regions in the coating, while the agglomerated ZrB2 and SiC particles are the main reasons for the formation of loose regions in the coating. |
| Key words: ZrB2-SiC plasma spraying single splat microstructure densification |
