Electroless Deposition of Ni-P/SiO2 Composite Coating

Electroless deposit Ni-P/SiO2 composite coating was performed on the steel substrate, DIN EN 10130. The preparation of nickel coating included two main steps. In the first step, the fraction of SiO2 particles sized the tens of nanometres was obtained by sedimentation. In the second step, the composite coating was plated on the steel substrate. The actual deposition process contains the deposition of plain Ni-P interlayer which served as the nucleation center for the deposition of Ni-P/SiO2 composite coating with co-deposited SiO2 particles. The morphology of deposited composite coating was studied by scanning electron microscope (SEM). Amount of individual elements in deposited coatings was determinated by EDS analysis. The microhardness of deposited composite coating was subsequently compared with microhardness value of the plain Ni-P coating.