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1283 |
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Wednesday, June 04, 2008, Room 08 8:40 AM Pre- and Post-Treatment Thermal sprayed coatings must be regarded as part of a production process, in order to produce superior quality and performance new possibilities in pre- and post-treatment have to be discussed |
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Effect of diffusion treatment on interface microstructure between thermally sprayed Co-based self-fluxing alloy coating and steel substrate |
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Kazunori Sakata* / FUJIKIKOSAN CORPORATION, JAPAN Soichiro Fujita/ Kyushu University, Japan Hirofumi Miyahara/ Kyushu University, Japan Keisaku Ogi/ Oita National College of Technology, Japan |
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Effect of diffusion treatment was investigated on the interface microstructure between Co-based self-fluxing alloy coating and mild steel substrate to improve the bonding strength. The diffusion treatment of thermally sprayed Co-based alloy coatings on steel substrate?@were?@carried out at 1373K to 1418K for 600s to 7200s under an Ar atmosphere. The diffusion treatment allows each element present in the coating and substrate to diffuse and improves the metallurgical bonding at the interface. Co, Cr, W, Ni and Si diffuse from the sprayed coating layer to the substrate, and Fe and Mn diffuse from the substrate to the coating. The diffusion layer at the interface is formed by this mutual diffusion. The width of the diffusion layer grows with increasing the temperature and the holding time, and the growth of the diffusion layer follows a parabolic rule. Furthermore, the apparent activation energy of the diffusion layer formation was calculated with about 360kJ/mol using the Arrhenius equation. |