Growth Kinetics of In Situ Fabricated Dense NbC Coatings on Gray Cast Iron

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• 作者：Liuliu Shen ; Yunhua Xu ; Nana Zhao…
• 关键词：dense niobium carbide coating ; diffusion model ; in situ ; kinetics ; macrostructure
• 刊名：Journal of Materials Engineering and Performance
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：26
• 期：1
• 页码：34-40
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Characterization and Evaluation of Materials; Tribology, Corrosion and Coatings; Quality Control, Reliability, Safety and Risk; Engineering Design;
• 出版者：Springer US
• ISSN：1544-1024
• 卷排序：26

文摘

In the present study, dense niobium carbide (NbC) coatings are fabricated by in situ techniques on gray cast iron (Fe) substrates at 1150 °C for 5 min, followed by a heat treatment at 990, 1010 and 1030 °C for 5, 10, 15 and 20 min. The microstructure, element composition and metallographic phase of the coating are characterized by scanning electron microscope, energy dispersive spectral and x-ray diffraction, respectively. Results show that the coating consists of NbC and α-Fe phases. NbC coating thickness ranges from 12.51 ± 1.4 to 29.17 ± 2.0 µm depending on the heat treatment temperature and time. In addition, the growth kinetics of dense niobium carbide coatings are estimated. A diffusion model based on Fick’s laws is used to explore the carbon diffusion coefficients of the dense NbC coating in the range of heat treatment temperatures in which the experimental results of the kinetics of the niobium carbide coating are in good agreement with those estimated using diffusion model.