热氧化对Zr基块体金属玻璃腐蚀行为的影响

Effect of Thermal Oxidization on Corrosion Behavior of Zr-based Bulk Metallic Glass

本文系统研究了空气中热氧化对Zr-Cu-(Nb)-Ag-Al-Be块体金属玻璃在含Cl^-溶液中腐蚀行为的影响。热氧化后:样品表面生成0.3~0.4μm厚的氧化层,层内Al和O富集;含Nb样品点蚀电位和自然腐蚀电位明显增大,不含Nb样品极化曲线却无明显变化;浸泡实验中样品表面的腐蚀坑密度显著降低,腐蚀坑内Cu富集、Zr贫化。X射线光电子能谱结果显示热氧化后含Nb样品表面含有Nb_2O_5和更低的Cu含量,而其它元素与不含Nb样品相似。因此,热氧化能更显著地改善含Nb样品耐蚀性能的原因可能是含Nb_2O_5的氧化膜更加致密,以及该氧化层能更有效阻碍Cl^-扩散。

Influence of thermal oxidization on corrosion behavior of Zr-Cu-（Nb）-Ag-Al-Be bulk metallic glasses（BMGs）in Cl^- contained solution were systematically studied.After thermal oxidization：thickness with 0.3~0.4μm and Al,O enriched oxide layer were formed at surface;corrosion potential and pitting potential of Nb-contained BMG were evidently enhanced,while Nb-free BMG did not show apparently change;surface pit density of BMGs in immersion test decreased and Cu was enriched and Zr depleted inside the pits.In Nb-contained surface,Nb2O5 existed and Cu content was low,but contents of other elements were similar to Nb-free BMG from X-ray photoelectron spectroscopy analyzes.Nb2O5-contained oxide film is denser and Cldiffusion was more effectively impeded,causing greater improvement of corrosion resistance of Nb-contained BMG after oxidation.