A Comparative Study on Ni-Based Coatings Prepared by HVAF, HVOF, and APS Methods for Corrosion Protection Applications

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• 作者：E. Sadeghimeresht ; N. Markocsan ; P. Nylén
• 关键词：corrosion ; OCP ; process optimization ; potentiodynamic polarization ; thermal spraying
• 刊名：Journal of Thermal Spray Technology
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：25
• 期：8
• 页码：1604-1616
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Surfaces and Interfaces, Thin Films; Tribology, Corrosion and Coatings; Characterization and Evaluation of Materials; Operating Procedures, Materials Treatment; Analytical Chemistry;
• 出版者：Springer US
• ISSN：1544-1016
• 卷排序：25

文摘

Selection of the thermal spray process is the most important step toward a proper coating solution for a given application as important coating characteristics such as adhesion and microstructure are highly dependent on it. In the present work, a process-microstructure-properties-performance correlation study was performed in order to figure out the main characteristics and corrosion performance of the coatings produced by different thermal spray techniques such as high-velocity air fuel (HVAF), high-velocity oxy fuel (HVOF), and atmospheric plasma spraying (APS). Previously optimized HVOF and APS process parameters were used to deposit Ni, NiCr, and NiAl coatings and compare with HVAF-sprayed coatings with randomly selected process parameters. As the HVAF process presented the best coating characteristics and corrosion behavior, few process parameters such as feed rate and standoff distance (SoD) were investigated to systematically optimize the HVAF coatings in terms of low porosity and high corrosion resistance. The Ni and NiAl coatings with lower porosity and better corrosion behavior were obtained at an average SoD of 300 mm and feed rate of 150 g/min. The NiCr coating sprayed at a SoD of 250 mm and feed rate of 75 g/min showed the highest corrosion resistance among all investigated samples.