镁合金水热法表面处理  

Surface Treatment of Magnesium Alloy Using a Hydrothermal Route

作　　者：张满意[1] 郭兴伍[1] 杨海燕[1] 王渠东[1] 丁文江[1] 

机构地区：[1]上海交通大学轻合金精密成型国家工程研究中心金属基复合材料国家重点实验室,上海200240

出　　处：《材料保护》2010年第7期14-17,共4页Materials Protection

基　　金：上海交通大学国防基金项目(07GFH-GB01-016)

摘　　要：镁合金常规化学转化膜中含有Cr6+,对人体和环境有很大危害,且膜层较薄,耐蚀性有限,因此,采用水热法对其进行处理。通过场发射扫描电镜、X射线衍射和电化学测试方法,分别对水热法处理后的Mg-Nd-Zn-Zr镁合金表面膜层的形貌、相组成和耐蚀性能进行了研究。结果表明,形成的表面膜层主要由球形颗粒状和层片状的Mg(OH)2相组成,膜层厚度约可达20μm,且与基体结合牢固;经水热法处理后的镁合金在质量分数3.5%的NaCl水溶液中的开路电位比未处理的镁合金基体的正移了230mV,腐蚀电流密度降低了约1个数量级,且在阳极区出现了明显的钝化现象。Mg alloy was surface-modified by using a hydrothermal method. The surface morphology, microstructure and corrosion resistance of the coatings formed on magnesium alloy surface were studied by means of field emission scanning electron microscopy, X-ray diffraction and electrochemical testing. Results show that the surface-modified layer on Mg alloy mainly consists of spherical and plate-like particulates of Mg(OH)2, and has good adhesion to Mg alloy substrate and a thickness of about 20 μm. The open circuit potential of treated Mg alloy in aqueous solution of 3. 5 % NaCl positively moved by 230 mV as compared with that of untreated Mg alloy. The corrosion current density of the treated Mg alloy was lowed by one order of magnitude, and obvious passivation appeared in anodic area.

关 键 词：镁合金 水热法 耐腐蚀性能 

分 类 号：TG174.45[金属学及工艺—金属表面处理]