STUDY ON THE FABRICATION OF NANO-SiC/Ni-P COMPOSITE COATINGS WITH THE ASSISTANCE OF ELECTROMAGNETIC-ULTRASONIC COMPOUND FIELD

Electroless nanocomposite platings were fabricated with the assistance of electromagneticultrasonic fields with controlled parameters. The effect of the complex field on the composite platings' deposition process was investigated. The results show that composite coatings fabricated by a complex magnetic field have better density and homogeneity than those produced without the above external fields. The time-step deposition studies indicate that the extra magnetic field accelerates the motion of the composite particulates in the bath through the action of the Lorentz force and promotes the nucleation and growth process of composite particulate clusters. The energy generated by the ultrasonic vibration activates the substrate surface and promotes the deposition of Ni2+ in the plating solution at the substrate surface. The nanoindentation hardness of these composite coatings is approximately 0.15 GPa. While the complex field is functioning, ultrasonic and magnetic interactions play an important role in the fabrication of the uniform and dense nano-SiC/Ni-P composite coatings, which consist of amorphous spherical Ni-P/SiC particle clusters of 200 nm diameter.