| 摘要: |
| 利用等离子熔覆同轴双筒送粉工艺，在Q235基板上制备了多层WCNi成分渐变的梯度涂层，结果表明：涂层中WC颗粒大部分被溶解，在随后的快速冷却中，有两类碳化物组织析出，组织特征与WCNi的含量有关。当WCNi含量小于20%时，析出粗大树枝晶基体混合片层状共晶碳化物组织；当WCNi含量大于30%时，析出块状初生碳化物组织。未完全溶解的WC颗粒呈圆角形，并与基体之间形成合金过渡层。梯度涂层中各层间形成了冶金过渡，其主要物相有γFe、WC、Fe3C、Fe3W3C、Cr7C3。涂层的硬度明显高于基体，但受WC的溶解及析出碳化物的大小及分布不均影响，梯度涂层的硬度分布波动起伏较大。 |
| 关键词: 等离子熔覆 WC-Ni 梯度涂层 碳化物 |
| DOI： |
| 分类号: |
| 基金项目: |
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| Preparation, Microstructure and Performance of WC-Ni Reinforced Febased Graded Coating |
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YUAN Youlu1,2, LI Zhuguo2
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1. Department of Materials Engineering, Hubei University of Automotive Technology, Shiyan 442002, Hubei; 2. School of Material Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240
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| Abstract: |
| A multilayer graded coating of WCNi reinforced Febased matrix was prepared on Q235 steel plate by plasma cladding with a coaxial feeding powder system. Results show that most of the WC particles are dissolved in the Febased matrix, and two types of carbides are precipitated in the follow cooling stage. One is coarse dendrites mixed with lamellar eutectics carbides when WCNi content is less than 20%; the other is polygonal block primary carbides when WCNi content is more than 30%. The halfdissolved WC particles are all with round angles, and an alloy reaction layer forms between the particles and the matrix. The main phases of the coating are γ Fe, WC, Fe3C, Fe3W3C, and Cr7C3. Microhardness of the graded coating is higher than that of the substrate; however is fluctuated through the coating due to the dissolution of WC and the inhomogeneous distribution of the precipitated carbides. |
| Key words: plasma cladding WC-Ni graded coating carbides |
