Electrodeposition of nickel-tungsten alloys under ultrasonic waves: Impact of ultrasound intensity on the anticorrosive properties.

Electrodeposited Ni-W alloy assisted by high-intensity ultrasound was evaluated considering the nominal power effect on the anticorrosive property. Temperature profiles demonstrated that using a nominal power of 400 W, the electrolytic bath at 30 °C reached values of 39 ± 1 °C. The maximum acoustic power corresponded to 6.7% of the nominal power value at 400 W. Increasing the nominal power from 0 to 400 W; the Ni content decreased from 85.3 to 75.2 wt%, and the W content increased from 15.1 to 25.1 wt%. The deposited coating at 200 W and 300 W had a smooth, homogeneous, and uniform surface. At 400 W, the acoustic cavitation promoted erosion, affecting the coating surface. X-ray diffraction analysis indicated that the nominal power of 200 W promoted electrodeposition of the NiW structure with the plane (111) as a preferred orientation. The crystallite size decreased for the planes (111) and (200) when increased nominal power from 100 to 200 W. The optimum condition for the improved corrosion resistance occurred with the nominal power of 200 W, providing a polarization resistance of 23.42 kΩ cm.