Study Of The Electrochemiscal Properties And Fractal Of Electroless Deposition Co-Fe-B-RE Alloy Films

The electrochemical properties and fractal of the electroless depositionCo-Fe-B-RE alloy films were studied. On the basis of the optimum formulation ofelectroless deposition Co-Fe-B alloys, effects of RE on electrochemicalproperties(TAFEL curves, cyclic voltammetry curves and A.C. impedance curves)of the coating were studied in 3% NaCl, 3% HCl, 50% H₂SO₄, 20% NaOH and 10%HNO₃, five kinds of solution. Effects of different kinds of solution on corrosion ofcoating were obtained, and its micromorphologies were observed. Fractaldimensions calculated by AFM images express the micromorphology properties. Onthe basis of the optimum formulation adding different kinds of RE, different kindsof RE and different contents of RE were added to electroless deposition Co-Fe-Balloy coatings. The effects of RE on electrochemical properties and plating ratewere measured in different kinds of solutions. The mechanism of action andinfluence mode on the process, structure, propertics and electrochemical corrosionof Co-Fe-B alloy coating were discussed, and it was considered that the relationbetween fractal dimensions and corrosion, in order to obtain the electrolessdeposition cobalt-base alloy film with excellent over-all soft magnetic properties.The results showed that the suitable addition of RE enable to enhance the propertiescorrosion resistance of coatings in 3% NaCl solutions, with the increasingaddition of Ce, the corrosion potential of TAFEL curve is a negative shift thenpositive shift, reductive peak potential of cyclic voltammetry curves first positiveshift then negative shift. When Ce addition equals to 0.8g/L, the corrosionresistance properties are the best. For different kinds of RE, with the increasingatomic number of RE, corrosion resistance properties is increasing first thendecreasing. Adding Gd, Tb or Dy is rather than adding Y, La or Ce. but in 3% HCl,50% H₂SO₄, 20% NaOH solutions, with the addition of RE corrosion resistanceproperties is decreased instead of enhancing. When adding behind atomic numberRE elements, corrosion resistance properties reduce less.By Height-relatedFunction, the fractal dimension can be calculated from the AFM images. We can seethe electtoless deposition Ce Co-Fe-B alloy contings with re joined, the fractaldimensions increase, and the corresponding contings are close, uniform, dense.When Ce reaches 0.6-0.8 g/L, fractal dimensions are larger. For different kinds ofRE, adding behind atomic number RE elements, fractal dimension are greaterthan adding before atomic number RE elements. The fractal dimensions and corrosion resistance properties of the coating in 3ï¼…NaCl solutions have acorresponding relationship, the fractal dimension are larger, the corrosionresistance properties are better in 3ï¼…NaCl solutions.