Effect of critical plasma spray parameter on properties of hollow cathode plasma sprayed alumina coatings
Effect of critical plasma spray parameter on properties of hollow cathode plasma sprayed alumina coatings
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DOI：
10.1016/j.surfcoat.2008.08.030
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发表时间：
2008-10
影响因子：
5.4
通讯作者：
S. Yugeswaran;V. Selvarajan;D. Seo;K. Ogawa
中科院分区：
文献类型：
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作者：
S. Yugeswaran;V. Selvarajan;D. Seo;K. Ogawa
研制了一台20 kW空心阴极等离子喷枪，并在低碳钢基体上采用不同的临界等离子喷涂参数（CPSP：0.12，0.24，0.36，0.48）喷涂氧化铝涂层，研究了喷枪的性能。CPSP被定义为焊炬输入功率与初级等离子体形成气体流速之间的比率。研究了等离子喷涂对涂层组织、孔隙率、显微硬度、表面粗糙度、滑动磨损和冲蚀磨损性能的影响。研究了不同CPSP下等离子体射流的激发效率和激发温度。利用扫描电镜和X射线衍射仪对涂层的微观结构和相组成进行了分析。XRD分析表明，氧化铝颗粒在等离子喷涂过程中达到足够的熔融状态之前，在基板上的冲击速度与传统的等离子喷涂。实验结果表明，CPSP对沉积氧化铝涂层的显微结构和其他性能有显著影响。空心阴极等离子体喷枪是一种适用于低输入功率水平下涂覆致密陶瓷材料的工具。
A 20 kW hollow cathode plasma spray torch was manufactured and its performances were examined by spraying alumina coatings on mild steel substrates with different critical plasma spray parameters (CPSP: 0.12, 0.24, 0.36, 0.48). CPSP is defined as the ratio between the torch input power and primary plasma forming gas flow rate. The effects of CPSP on the microstructure, porosity, microhardness, surface roughness, sliding wear and erosive wear properties of the coatings were investigated. The electrothermal efficiency and the excitation temperature of the plasma jet were also investigated for different CPSP. The microstructure and phase composition of the alumina coatings were examined using scanning electron microscope and X-ray diffraction (XRD) analysis respectively. XRD analysis revealed that alumina particles during plasma spraying reach sufficient melting state prior to the impact on the substrate with a velocity comparable to that of conventional plasma spraying. The experimental results have shown that the CPSP has significant influence on the microstructure and other properties of the deposited alumina coating. It also showed that the hollow cathode plasma spray torch is a suitable tool to coat the dense ceramic materials with low input power levels.