摘要
采用金属模铸造法制备Mg-4.5Zn-xSn（x=0,1,2,3,4,mass%）合金。利用X-射线衍射仪、扫描电镜、电化学方法和浸泡实验研究Sn元素含量对Mg-4.5Zn合金显微组织和耐蚀性能的影响。结果表明：Mg-4.5Zn合金组织由α-Mg和粗大的（α-Mg＋Mg7Zn3）共晶体组成;加入2 mass%Sn时合金中生成了少量的Mg2Sn相,（α-Mg＋Mg7Zn3）共晶体变为球状,弥散分布在枝晶界上;当Sn含量超过2 mass%时,随着Sn含量的增加Mg2Sn相数量增多、并长大粗化,部分（α-Mg＋Mg7Zn3）共晶体转变为三角形状;合金耐蚀性能随Sn含量的增加先变好后变差,Mg-4.5Zn-2Sn合金耐腐蚀性能最好,具有最小的自腐蚀电流密度（149μA·cm^-2）以及最大的电荷转移电阻（100.3Ω·cm^-2）和腐蚀膜层扩散电阻（33.88Ω·cm^-2）。
Mg-4.5Zn-xSn（ x = 0,1,2,3,4,mass%） alloys were prepared by metal mould casting method. The effect of Sn content on microstructure and corrosion properties of the alloy in simulated body fluids was characterized by means of X-ray diffraction,scanning electron microscopy,electrochemical method and immersion test. The results show that the microstructure of as-cast Mg-4. 5Zn alloy consists of α-Mg and coarse thread-like（ α-Mg ＋ Mg7Zn3） eutectic. When 2 mass% Sn is added into the alloy,a small amount of Mg2Sn phase is formed in the alloy,and the（ α-Mg ＋ Mg7Zn3） eutectic is transformed into the spherical and dispersed on the dendrite boundary.When Sn content exceeds 2 mass%,with the increase of Sn content,the volume fraction of the Mg2Sn phase increases and becomes coarser. In addition,the morphology of a few volume fraction of（ α-Mg ＋ Mg7Zn3） eutectic changes into triangle structure. The corrosion resistance of the Mg-4.5Zn-xSn alloys first increases then decreases with the increasing of Sn content. The corrosion resistance of Mg-4.5Zn-2Sn alloy is the best. It has the smallest self-corrosion current density（ 149 μA·cm^-2）,the largest charge transfer resistance（ 100. 3 Ω·cm^-2） and the diffusion resistance in corrosion film（ 33. 88 Ω·cm^-2）.
作者
王建利
裴娟
袁姣娜
朱美玲
杨忠
李建平
WANG Jian-li;PEI Juan;YUAN Jiao-na;ZHU Mei-ling;YANG Zhong;LI Jian-ping(School of Materials and Chemical Engineering, Xi＇an Technological University, Xi＇an 710021, China;Shaanxi Engineering Research Center of Mg/Al Light Metallic Alloys and Composites, Xi＇an 710021, China;Shaanxi Key Laboratory of Optoelectronic Functional Materials and Devices, Xi＇an 710021, China)
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2018年第6期26-34,共9页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金(51201120)
陕西省教育厅重点实验室项目(17JS053)
陕西省科技统筹创新工程计划项目(2016KTZDGY-04-01)
