电沉积条件对非晶态Fe-Mo合金结构及表面性质的影响

Effects of Electrodeposition Conditions on the Structure and Surface Characteristics of Amorphous Fe Mo Alloys

利用ＸＲＤ、ＳＥＭ和ＸＰＳ等手段研究了电解液中ｘ（Ｍｏ）（Ｍｏ在Ｍｏ＋Ｆｅ中的摩尔分数）、电流密度及温度变化对电沉积非晶态Ｆｅ－Ｍｏ合金的结构和表面性质的影响．溶液中主要含有ＦｅＳＯ４、Ｎａ２ＭｏＯ４、Ｈ３Ｃｉｔ和ＮａＣｌ，ｐＨ值３～５．当ｘ（Ｍｏ）大于５０％，电流密度高于２５ｍＡ／ｃｍ２，温度低于４０℃时有利于形成非晶态结构．合金沉积层的表面呈颗粒状且有微裂纹，表面的化学性质很活泼，容易形成含低价Ｍｏ的有色氧化物表面膜．非晶Ｆｅ－Ｍｏ合金沉积层在３％ＮａＣｌ溶液中的耐蚀性优于纯铁．

The effects of molybdenum content in the bath, current density and temperature on the structure and surface characteristics of amorphous Fe Mo alloys electrodeposited from the bath containing FeSO 4, Na 2MoO 4 , H 3Cit and NaCl (pH= 3～5) were investigated by using XRD, SEM and XPS. The results show that amorphous Fe Mo alloys can be obtained as long as the molar fraction of Mo in Mo/Mo+Fe in the bath is larger than 50%,the applied current density larger than 25 mA/cm 2 and the temperature of electrolyte lower than 40 ℃. The SEM observation of the microstructure of the electrodeposited Fe Mo alloys shows that the deposits contain numerous granules and cracks. According to the results of XPS, both Fe and Mo exist in metallic state in the bulk alloys but in oxidized states on the surface of the alloys. The results indicate that Fe and Mo on the surface of the alloys are easy to react with H 2O or O 2 in air resulting in the formation of oxide films. The corrosion resistance of the amorphous alloys in 3% NaCl solution surpasses that of pure iron.