Effects Of Plating Solution Compositions And The Temperature On The Electroless Fe-Zn Alloy Of The Stainless Steel Surface

As we all known,stainless steel has many disadvantages,such as low hardness,poor wear resistance,bigger friction coefficient and easy to cause local damage and corrosion,which results from the damage of surface passive film.Hence,surface treatment of stainless steel is welcome in order to improve the comprehensive performance.One of the most efficient methods is chemical plating,which is cheap and has the ability to be uniformed and deep plating.What is more,Fe Zn alloy,which is one of the alloy plating,display an excellent soft magnetic properties,good corrosion resistance,catalytic activity and some special physical and chemical properties,which can not display with the method of electroplating.For example,chemical deposit has good wear resistance and can be welded,which make this method widely used in the manufacture of electronic components and optical components.Recent years,there are few studies on chemical plating on Fe-Zn alloy.In this work,Fe-Zn binary alloy coating was prepared on a stainless steel substrate by chemical plating method.The effects of bath components and temperature on the deposition rate were studied by using orthogonal test and single factor variable test.The influence of parameters on coating hardness,anti corrosion performance and structure were investigated by micro hardness tester,SEM.The results show that the order of the influence of bath composition on the plating rate is ZnSO₄·7H₂O,C₄H₄O₆KNa·4H₂O,FeSO₄·7H₂O,NaH₂PO2·H₂O,the key to controlling the deposition rate is Zn ions in the bath concentration;Coating anti corrosion performance is closely related to the concentration of Zn SO₄·7H₂O and FeSO₄ · 7H₂O;The effects of electroless plating solutions composition on the microhardness of plating followed the order FeSO₄·7H₂O,NaH₂PO₂·H₂O,C₄H₄O₆KNa·4H₂O,ZnSO₄·7H₂O.Namely iron ion deposition is the hinge of the hardness of plating.With the plating temperature increasing,the Fe-Zn alloy plating deposition rate and micro-hardness are the increases firstly and then decrease.Electroless Fe-Zn alloy coatings optimum conditions: Na OH 35g/L,FeSO₄·7H₂O 8g/L,Zn SO₄·7H₂O 7g/L,H₃BO₃ 1g/L,C₄H₄O₆KNa·4H₂O 67g/L,NaH₂PO2·H₂O 9g/L,brightener 1g/L,plating temperature is 55?.Fe-Zn alloy plating hardness values and coating deposition rate reached a maximum 5.46 mg/?cm2·h?and 534 HV Under optimum conditions.Coating SEM analysis showed that the coating uniform particle size,tightly packed.EDS analysis showed the zinc content of the coating 14.83?,iron content is 85.17?,without other impurities.