PREPARATION OF Fe-Zn ALLOY DEPOSITS BY ELECTROLESS PLATING AND THE STUDY OF ITS PROPERTY

In this thesis, electroless plating and its deposition principle were briefly introduced. The progress of electroless plating in the past decade was summarized which includes nickel based alloys, cobalt basd alloys, copper based alloys and iron based alloys. The binary amorphous alloy Fe-Zn was obtained on copper substracts by electroless plating at the first time. The investigation for the plating procedure indicates, the practical optimum bath for Fe-Zn amorphous alloy was : FeSO4 ?7H2O 8g/l, ZnSO4 -7H2O 7g/l, KNaC4H4O6 -4H2O 65g/l, NaH2PO2 -H2O 8g/l, NaOH 35g/l , H3BO3 lg/1 , detrin lg/1; plating temperature: 55癈, and plating time: 20 minutes. The content, surface appearance and structure of deposits were studied. The corrosion resistance characters of electroless plating Fe-Zn in 10% NaOH Solution and 3.5% NaCl solution were alsostudied. The results indicate that the deposits had better corrosionresistance character than other iron based deposits. The dependence between the ratio of ZnSO4/(ZnSO4+FeSO4) in solution and the deposits microhardness was studied.lt showed that amorphous state deposit had higher value. After heat treatment at 300-400 癈, the microhardness of deposits got highest value.