Modifying Action of Ultrasonic Irradiation and Rare Earth Metal Cerium on Electroless Co-Ni-B Alloy Coatings

By plasma transmitting spectrograph,electron energy spectrometer,X-ray diffractometer,transmission electron microscopy and micro-hardometer,the depositing speed of electroless Co-Ni-B plating baths,chemical composition,crystal structure and microhardness of the alloy coatings were inspected and analyzed with ultrasonic and rare earth metal cerium intervening in electroless Co-Ni-B plating.The results show that the depositing speed of electroless Co-Ni-B alloy is obviously increased under these conditions.The content of cerium is also increased in electroless Co-Ni-B alloy coatings with ultrasonic intervening in the plating.Under the simultaneous action of ultrasonic and rare earth metal cerium,the chemical compositions of electroless Co-Ni-B alloy coatings are changed,and electroless Co-Ni-B alloy with amorphous structure is transformed to electroless Co-Ni-B-Ce alloy with microcrystalline or crystalline structure.In this way microhardness of the coatings is increased remarkably.