相组成及其耐蚀性
(西安理工大学 材料科学与工程学院， 西安 710048)
摘 要: 利用SEM，XRD及盐雾腐蚀等试验手段，研究了MB8镁合金微弧氧化陶瓷层生长过程中显微缺陷与相组成的变化规律及其对耐蚀性的影响。结果表明：微弧氧化初期，陶瓷层致密，几乎观察不到显微缺陷，随着处理时间的延长及陶瓷层的增厚，其外侧开始出现孔洞类缺陷，直至90%厚度范围布满相互交错的不规则孔洞；陶瓷层主要由MgO， MgSiO3，MgAl2O4和非晶相组成，随着厚度的增加，陶瓷层中MgO的比例不断增加，而非晶相含量逐渐减少；短时间微弧氧化处理有利于制取以非晶相为主的致密无缺陷的耐蚀陶瓷层。
关键字: 镁合金；微弧氧化；非晶相；腐蚀
ceramic coating formed by micro-arc
oxidation on magnesium alloys and
their influence on corrosion-resistance
（School of Materials Science and Engineering，
Xi′an University of Technology，Xi′an 710048，China）
Abstract:The change regulation of microflaw and phases constitution in the process of growth of ceramic coating formed by micro-arc oxidation on magnesium alloys and their influence on corrosion-resistance were studied by SEM, XRD and salt spray tests. The results show that in the initial stage of micro-arc oxidation the obtained ceramic coating is compact and nearly no microflaw can be observed，the microflaws like holes begin to appear in the exterior and finally irregular holes fill with 90% of the thickness range. The ceramic coating is mainly composed of MgO, MgSiO3, MgAl2O4 and non-crystal phase. The proportion of MgO in the coating increases continually with the thickness increasing，but the proportion of non-crystal phase decreases gradually. The micro-arc oxidation of short time is beneficial to preparing compact and no flaw ceramic coating mainly composed of non-crystal phase.
Key words: magnesium alloy; micro-arc oxidation; non-crystal phase; corrosion
