(陜西理工學院 材料科學與工程學院，漢中 723001)
摘 要: 采用X射線衍射儀、掃描電子顯微鏡、能譜儀、透射電子顯微鏡、全浸腐蝕及中性鹽霧腐蝕試驗等方法，對比研究Zn-0.5Al-1.5Mg、Zn-2Al-1.5Mg和Zn-2Al-1.5Mg-0.3Si(質(zhì)量分數(shù)，%)合金鍍層的組織與性能，探討Al和Si對熱浸Zn-Al-Mg合金鍍層組織和耐腐蝕性能的影響。結果表明：三合金鍍層的組成相是Zn相、Al相和MgZn2相；Zn-0.5Al-1.5Mg合金鍍層由塊狀富Zn相和晶界Zn+MgZn2二元共晶組織組成，Zn-2Al-1.5Mg合金鍍層由塊狀富Zn相和晶界Zn+Al+MgZn2三元共晶組織組成，Zn-2Al-1.5Mg-0.3Si合金鍍層由塊狀富Zn相、晶界Zn+Al+MgZn2三元共晶組織和針狀相Mg2Si組成；Al、Mg和Si主要分布在晶界，Al和Si有細化鍍層晶粒作用，添加Si能提高Zn-Al-Mg合金鍍層的耐腐蝕性能。
關鍵字: Zn-Al-Mg合金；Zn-Al-Mg-Si合金；熱浸鍍；鍍層組織；耐腐蝕性能
（School of Materials Science and Engineering, Shaanxi University of Technology, Hanzhong 723001, China）
Abstract:The microstructure and properties of Zn-0.5Al-1.5Mg, Zn-2Al-1.5Mg and Zn-2Al-1.5Mg-0.3Si (mass fraction, %) alloy coatings were comparatively studied, and the effects of Al and Si on the microstructure and the corrosion resistance of hot dipping Zn-Al-Mg alloy coatings were investigated by X-ray diffraction, scanning electron microscope, energy dispersive spectrometer, transmission electron microscope, full immersion corrosion and neutral salt spray test. The results show that the composition phases of three alloy coatings are Zn, Al and MgZn2 phases. Zn-0.5Al-1.5Mg alloy coating is composed of bulk Zn-rich phase and Zn+MgZn2 eutectic structure at the grain boundary, Zn-2Al-1.5Mg alloy coating is composed of bulk Zn-rich phase and Zn+Al+MgZn2 eutectic structure at the grain boundary, Zn-2Al-1.5Mg-0.3Si alloy coating is composed of bulk Zn-rich phase, Zn+Al+MgZn2 eutectic structure at the grain boundary and acicular Mg2Si. The Al, Mg and Si distribute mainly at the grain boundary. The Al and Si possess the functions of refining the grain size. The corrosion resistance can be enhanced by the addition of Si in Zn-Al-Mg alloy coating.
Key words: Zn-Al-Mg alloy; Zn-Al-Mg-Si alloy; hot-dipping; coating microstructure; corrosion resistance
