WC粒度对超音速火焰喷涂WC-10Co-4Cr涂层耐腐蚀性能的影响

发布时间：2018-04-08 21:06

本文选题：超音速火焰喷涂　切入点：WC-Co-Cr　出处：《粉末冶金材料科学与工程》2015年01期

【摘要】：采用制粒-高温快速烧结法制备两种分别含亚微米级和微米级WC粒径的WC-10Co-4Cr喷涂粉末,并用超音速火焰喷涂(HVOF)技术在45#钢基体上制备涂层;利用扫描电子显微镜和电化学工作站分别对涂层的显微形貌及耐腐蚀性能进行分析检测,探讨WC粒度对涂层耐腐蚀性能的影响和涂层的电化学腐蚀机理。研究结果表明:两种涂层组织致密,界面结合良好;含亚微米级WC粒径的涂层具有相对较低的孔隙率,使其涂层的耐腐蚀性能优于含微米级WC粒径的涂层。在3.5%Na Cl溶液中涂层的硬质相WC和粘结相Co发生电偶腐蚀,且低电位的Co相优先腐蚀,导致WC颗粒脱落,出现凹坑及点蚀现象。
[Abstract]:Two kinds of WC-10Co-4Cr sprayed powders containing submicron and micron WC particle sizes were prepared by granulation and high temperature rapid sintering. The coatings were prepared on 4steel substrates by supersonic flame spraying (HVOF) technique.The microstructure and corrosion resistance of the coatings were analyzed by scanning electron microscope (SEM) and electrochemical workstation. The effect of WC particle size on the corrosion resistance of the coatings and the electrochemical corrosion mechanism of the coatings were discussed.The results show that the microstructure of the two coatings is compact and the interface is well bonded, and the coating with submicron WC particle size has relatively low porosity, which makes the corrosion resistance of the coating better than that of the coating containing micron WC particle size.In 3.5%Na Cl solution, the hard phase WC and bonding phase Co are galvanically corroded, and the low potential Co phase is preferentially corroded, resulting in the exfoliation of WC particles and the occurrence of pit and pitting corrosion.
【作者单位】：中南大学粉末冶金国家重点实验室;
【基金】：国家自然科学基金资助项目(51175516) 湖南省杰出青年基金资助项目(10JJ1009) 粉末冶金国家重点实验室创新基金资助项目(32840102505)
【分类号】：TG174.4

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