Electrodeposition of Ni-P/Ni-Co bilayer coating on St37 steel

The surface characteristics of engineering components determine their durability and performance during the service condition. The goal of this investigation is to study the effect of applied current density on microhardness of the Ni-P/Ni-Co bilayer coating. Both Ni-P interlayer and Ni-Co top layer were electrodeposited using direct current (DC). The Ni-P layer was electrodeposited on polished St37 steel substrates followed by deposition of Ni-Co at various current densities, i.e., 4-6 A dm-2. The Vickers microhardness tester was used to evaluate the microhardness of the electrodeposited coatings. Results show that the applied current density has a significant influence on microhardness of the bilayer coating, where increasing current density from 4 to 5 A dm-2 leads to a 34 HV increment in the microhardness value. Note that further increase in the current density inversely affect the mechanical properties

کلیدواژه ها:

Ni-Co ، Ni-P ، Bilayer coating ، Electrodeposition ، Microhardness.