Preparation And Wear,Corrosion Resistance Of Ni-based Alloy Coatings

The excellent wear resistance and corrosion resistance of Ni-based alloys have gradually replaced the chrome plating,which has become a hot topic in recent years.At present,there have been many methods for preparing nickel-based alloys,and the pulse plating method has been widely used with its simple operation and high repeatability.In this paper,it used 45^#steel as the cathode and pure graphite plate as the anode to prepare Ni-based alloy coatings by the pulse plating technology.In addition,Ni SO₄·6H₂O was selected as the nickel source,and the co-deposition of Ni-W,Ni-P,and Ni-W-P alloy coatings was achieved by adjusting the concentration of tungsten salt and/or phosphorus salt,peak current density,and other conditions.Studying the influence of pulse duty cycle,and the peak current density on the structure of the Ni-W,Ni-P,and Ni-W-P alloy coatings,and the influence on the wear resistance,corrosion resistance and tribocorrosion resistance were investigated.The main research contents and results are as follows:（1）It takes Na WO₄·2H₂O as a tungsten source for preparing Ni-W alloy coating.Studying the influence of duty cycle and current density on the structure and properties of Ni-W alloy coatings.The structure of different Ni-W alloy coatings was characterized.The results showed that with the increase of duty cycle,the coating structure changes from amorphous to crystalline state and then to amorphous.With the increase of current density,the coating structure changes from crystalline state to amorphous.Properties of the Ni-W alloy coating shows that the Ni-W alloy coatings with a 50%duty cycle has good wear resistance and corrosion resistance,which attributed to samller crystallite size and higher tungsten content.And the Ni-W alloy coating with a current density of 25 A/dm²has a small wear rate.The Ni-W alloy coating with a current density of 20A/dm² has good corrosion resistance.Corrosion and wear have synergistic effects in the abrasive behavior of Ni-W alloy coatings.（2）It takes H₃PO₃ as a phosphorus source for preparing Ni-P alloy coating.Studying the influence of duty cycle and current density on the structure and properties of Ni-P alloy coatings.The structure of different Ni-P alloy coatings was characterized.The results showed that the duty cycle had less influence on the structure of Ni-P alloy coating,and it showed amorphous structure.With the increase of current density,the coating structure changed from mixed crystalstate to amorphous.Properties of the Ni-P alloy coating shows that 50%duty cycle has good wear resistance and 60%duty cycle has good corrosion resistance;Ni-P alloy coatings with 5 A/dm² have small wear rates.The Ni-P of 15A/dm²hasgoodcorrosionresistance.TheNi-Palloycoatinghasgood tribocorrosion resistance and wear plays a leading role.（3）It takes Na H₂PO₇·H₂O as a phosphorus source and Na WO₄·2H₂O as a tungsten source for preparing Ni-W-P alloy coating.Studying the influence of duty cycle and current density on the structure and properties of Ni-W-P alloy coatings.The XRD showed the duty cycle and current density had little effect on the structure of Ni-W-P alloy coatings,which showed amorphous.Properties of the Ni-W-P alloy coating shows that 50%duty cycle has good wear resistance and corrosion resistance;Ni-W-P alloy coatings with 3A/dm²have small wear rates and good corrosion resistance.The tribocorrosion resistance of Ni-W-P alloy coating showed wear plays a leading role.