The Study On The Microstructure And Properties Of Electroless Plating Multicompnent Cobalt Based Soft Magnetic Film With Rare Earth Joined

This paper determines the technological process, bath formularizstion and experimental parameter of electroless multicomponent cobalt based soft magnetic film with rare earth elements joined such as Co-Ni-B-RE and Co-Fe-B-RE by the means of perpendicular experiment and regression analysis. This paper also studies the active mechanism of rare earth elements, ultrasonic irradiation and magnetic field on the plating process, chemical component, surface configuration, microstructure and properties of electroless multicomponent cobalt based soft magnetic film in the way of examining in the component, microstructure and properties of such alloy. The result shows that with the addition of rare earth elements, ultrasonic irradiation and magnetic field, the chemical component, surface configuration, microstructure and properties of electroless Co-Ni-B and Co-Fe-B alloy changes remarkably. Such kind of change can be described as the followings. Firstly the depositing speed of electroless alloy bath is raised while the polarizability and cathodic overpotential are reduced; Secondly the surface quality of the alloy coating and adhesion of the coating and matrix are improved; Thirdly in the coatings the content of the elements in the transient group increases, but the content of cobalt decreased; Fourthly the amorphous structure is transformed to microcrystal structure and polycrystal structure; Fifthly the microhardness and wear resistance of the coating are enhanced; Sixthly coercitive force is reduced, and magnetoconductivity of the coating is increased; Lastly the magnetic intensity of the coating increases with the addition of energy and light rare earth elements such as Ce, La and decreases with the addition of heavy rare earth elements such as Y. On the other side, when the alloy coatings passes through the heat treatment under the temperature of 250℃ or 500℃, their properties will change. Such point can also be concluded as the followings: At first, their mechanical behavior will be improved; Then the value of He will be raised; And finally the values of their Ms and u will increase under the temperature of 250℃, but decrease under the temperature of 500℃.