【作者】 张翔；

【导师】 李子全；

【作者基本信息】 南京航空航天大学 ， 材料加工工程， 2006， 硕士

【摘要】 金属腐蚀与防护的研究具有重要的意义,热浸镀技术是提高钢铁耐腐蚀性的有效途径之一。锌铝合金是一种新型防腐蚀材料,其涂或镀后具有粘附性强,耐磨性和抗腐蚀性更好,工艺简单和成本低等特点,因而得到了较为广泛的应用,并成为国内外研究的热点。本文对在Zn-4.5%Al基体合金中添加少量合金元素RE、Mg和Ti的优化方案以及在助镀剂中引入CeCl₃,助镀工艺中引入超声波工艺对镀层厚度、表面质量和耐腐蚀性的影响进行了研究。在Zn-4.5%Al基体合金中对添加少量合金元素RE、Mg及Ti的微观组织及耐蚀性进行了研究。对添加单元合金试样的金相组织的观察和电化学测试的结果表明当RE、Mg和Ti的含量分别为0.10%、0.10%和0.03%时,微观组织及耐腐蚀性效果较为明显。以此进行正交试验,SEM、中性盐雾腐蚀和电化学测试结果表明Zn-4.5%Al-0.10%RE-0.05%Mg-0.05%Ti合金具有理想的共晶组织和很好的耐腐蚀性能;并对耐蚀机理进行了初步探讨,少量合金元素的加入对改善晶界腐蚀、细化晶粒的作用明显。在自制合金的基础上,采用正交试验对自制合金的助镀工艺进行了研究,对电化学试验数据的极差分析得到优化方案为助镀剂中添加CeCl₃含量为0.5wt%,助镀时间为3分钟,助镀温度为40℃。同时对超声波助镀工艺进行了研究,该工艺能一定程度提高热镀层的耐腐蚀性能。SEM、EDS表明在助镀剂中添加CeCl₃能一定程度使组织致密,厚度增加,表面平整;改善了热镀层的表面质量。通过XRD对自制合金和Galfan合金的腐蚀产物分析,腐蚀性能的提高不是因为腐蚀产物的改变所致。最后对自制合金的力学性能也进行了测试。相对基体合金和Galfan合金,其抗拉强度、断后伸长率和硬度有一定程度改善。学测试,中性盐雾腐蚀更多还原

【Abstract】 The study of metal corrosion and protection is significant, and Hot-Dipping technology is one of effective means to improve the corrosion resistance of steel and iron. Zn-Al alloy coatings as a new anticorrosive material owing to good viscidity, wear-resistance, corrosion resistance, simple process and low cost, have been applied far and wide and become a hot-spot of research. In this thesis, the optimum components of RE, Mg and Ti based on Zn-4.5%Al alloy and effects of CeCl₃ addition in infusion of assistant plating, as well as Ultrasonic assistant plating technics on the thickness, surface quality and corrosion resistance of the coatings have been investigated.Effects of RE, Mg and Ti additions on the microstructure and corrosion resistance of Zn-4.5%Al alloy were investigated. The results of morphology and electrochemistry test to the single addition alloy indicated that the effect was comparatively obvious when the single addition content of RE, Mg and Ti has been 0.10%, 0.10% and 0.03% respectively. Orthogonal experiments were carried out on the base of upper results. Results of SEM, neuter salt spray corrosion and electrochemistry test implied that excellent eutectic microstructure and corrosion resistance property were obtained in the Zn-4.5%Al-0.10%RE-0.05%Mg-0.05%Ti alloy. Finally, the mechanism of corrosion resistance was discussed, trace adiditions of the alloy elements have obvious effects on the refinements of intergranular corrosion and grains.The technics of assistant plating on self-made alloy coatings through orthogonal experiments were investigated in this work. The optimum process was that the content of CeCl₃ has been about 0.5wt%, the time of assistant plating has been 3 minutes and the temperature has been 40℃. We founded that the Ultrasonic technics could certainly enhance the corrosion resistance of the samples. The samples were characterized by scanning electron microscope （SEM） and energy dispersive spectrometer （EDS）, and the results indicated that the utility of infusion of assistant更多还原