电弧喷涂锌铝基涂层的组织与耐蚀性
Microstructure and Corrosion Resistance of Arc Sprayed Zn-Al Based Coatings
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摘要: 利用电弧喷涂在Q235钢基材表面分别制备了相同厚度的纯Al、Zn-Al与Zn-Al-Ni涂层,对比分析了三种涂层的微观组织,结合强度以及耐蚀性能。结果表明:三种涂层均具有良好的电弧喷涂成型质量,其中Zn-Al-Ni涂层呈现出少量fcc-Al相弥散分布于hcp-Zn相和fcc-Ni(Al)相的多相组织特征;在相同厚度下,Zn-Al-Ni涂层中Ni元素的引入能够显著提高涂层与基体之间的结合强度;与Zn-Al涂层相比,纯Al和Zn-Al-Ni涂层能够改善Q235钢在3.5%(质量分数)NaCl溶液中的耐腐蚀性能,且具有良好的耐盐雾腐蚀能力。Abstract: Pure Al, Zn-Al and Zn-Al-Ni coatings with the same thickness were prepared on the surface of Q235 steel substrate by arc spraying. The microstructure, adhesive strength and corrosion resistance of the three coatings were analyzed and compared. The results show that the three coatings all had good arc spraying forming quality, among which Zn-Al-Ni coating showed a characteristic of multiphase structure with a small amount of fcc-Al phase dispersing in hcp-Zn phase and fcc-Ni(Al) phase. At the same thickness, the introduction of Ni in Zn-Al-Ni coating could significantly improve the bonding strength between the coating and the substrate. The pure Al coating and Zn-Al-Ni coating could improve the corrosion resistance of Q235 steel in 3.5% (mass fraction) NaCl solution and had good salt spray corrosion resistance, compared with those of the Zn-Al coating.