The Effect of Sodium Hypophosphite, Temperature and Time in co-deposit Ni-P ？Coatings on 6061 Series Aluminum Substrate: An Environment-Friendly Alternative ？to Electrolytic Hard Metal Coatings

The autocatalytic electroless depositions, which form an alternative to the electrolytic deposition and do not require any external electrical power, are used in many industrial areas. Electroless nickel based plating has increased attention because of their high hardness, excellent corrosion, wear resistance very commonly. It also has the advantages of being applied to complex shaped parts. In this study, the hardness, metallic nickel and phosphorus contents of the electroless Ni-P coatings, the types of compounds formed after the heat treatment and their microstructural properties were investigated and the proporties of sodium hypophosphite, temperature and time parameters were examined. In addition Ni-P coatings, which are sensitive to environment and health, have been investigated a new alternative in the coating study carried out for 90 minutes to 950 HV. In addition, homogeneous Ni-P alloy coatings having a thickness of 20.6 microns depending on the reducing agent concentration and 10.9 microns depending on the coating time were obtaine