离子束混合对铁的水溶液腐蚀行为的影响

本文应用电化学及俄歇电子能谱等技术,研究了离子束混合对铁的水溶液腐蚀行为的影响,旨在探讨离子束混合作为一种材料表面改性的新途径,用于提高纯铁腐蚀性能的可能性。电化学动电位扫描的结果表明,纯铁表面真空沉积铬薄层(～400),经氩离子束轰击混合后,其阳极致钝电流密度(I_i)和维钝电流密度(I_m)较混合前均有数量级的降低,此种腐蚀性能改进的效果随轰击剂量的增加而增加。钝化膜的俄歇电子能谱分析结果表明,腐蚀性能的改进可归因于表面形成了一层富铬的以氧化膜为主的钝化膜,也与混合界面上形成的亚稳相有关。同时,发现经氩离子轰击后,在混合层及其附近的铁衬底中产生了“氩泡”为主的物理损伤.

THE EFFECT OF ION BEAM MIXING ON AQUEOUS CORROSION OF IRON

Electrochemical technique and Auger electron spectroscopy(AES)were employed for studies on the effect of aqueous corrosion of iron by means of ion beam mixing in order to envisage the possibility for developing a new approach in surface modification of materials. Fe specimens were deposited with Cr(～400)in vacuum and then bom- barded by argon ion beam at the dose range of 1·10~(14)～5~(15)Ar~+/cm~2. In comparing ion beam mixed specimens with unmixed ones,it is found that ion beam mixing reduces the anodic current I_i and I_m in anodic potentio- dynamic polarization curves by approximately one order of magnitude.This beneficial effect increases with bombardment dose of argon.AES result shows that this beneficial effect is mainly related with the formation of passive film with chromium oxide on the bombarded surface.And it is presumably associated with the formation of metastable phase on mixed boundary between the deposited layer and substrate. Transmission electron microscope examination has revealed that argon bub- bles were formed as main physical damage in mixed boundary layer and sub- strate in close vicinity to the original interface during argon bombardment.