Effect of electroplating temperature on microstructure, corrosion, and wear behavior of Ni-P-W-TiO2 coating

Nickel-phosphorus-titanium oxide coating is fabricated on the AISI 304L steel substrate using the electroplating method. Electroplating is performed at temperatures of 55 degrees C, 60 degrees C, and 65 degrees C, and the effect of electroplating temperature on microstructure, corrosion behavior, and wear behavior is investigated. The coatings are characterized using scanning electron microscopy (SEM). In order to investigate corrosion resistance, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests are performed in a 3.5% NaCl aqueous solution. A pin-on-disk test is employed to investigate the wear resistance of uncoated and coated samples. Sample micro-hardness is also measured by the Vickers hardness test. The results of potentiodynamic polarization and EIS tests show that the coating created at the temperature of 60 degrees C has the highest corrosion resistance (7058 omega.cm2) compared with the samples coated at temperatures of 55 degrees C (2115 omega.cm2) and 65 degrees C (2289 omega.cm2). Moreover, the results of the wear and micro-hardness test show that the composite coating formed at the temperature of 60 degrees C has the highest wear resistance and micro-hardness (677 Vickers) compared with the samples coated at temperatures of 55 degrees C (411 Vickers) and 65 degrees C (536 Vickers).