Laser cladding in-situ NbC particle reinforced Fe-based composite coatings with rare earth oxide addition

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• 作者：Qingtang Li ; Yongping Lei ; Hanguang Fu
• 关键词：Laser cladding ; Composite coating ; In situ ; Niobium carbide ; Rare earth oxide
• 刊名：Surface and Coatings Technology
• 出版年：25 January, 2014
• 年：2014
• 卷：239
• 期：Complete
• 页码：102-107
• 全文大小：2001 K

文摘

Over the past decade, researchers have demonstrated much interest in laser cladded metal matrix composite coatings for its good wear resistance, corrosion resistance and high temperature properties. The effects of RE on the microstructure and properties of laser coatings have also got more and more attention. In this paper, in situ Fe-NbC composite coatings with different CeO₂ addition were produced on die steel by laser cladding. The formation mechanism of NbC particles was analyzed. The effects of RE on microstructure and micro-hardness of coatings were investigated. It was revealed that larger NbC particles with hard edges formed around Nb particles, and smaller flocculent NbC particles formed by the chemical reaction of Nb and solid graphite in the molten pool. CeO₂ plays important roles in reducing micro-porosities, refining grains, and improving the precipitation of NbC. Therefore, the average micro-hardness and its smoothness from the top to the bottom of the coating were improved after adding CeO₂.