Ultrasonic irradiation assisted electroless Ni-P coating on magnesium alloy

Ultrasonic irradiation (UI) is applied to assist the electroless plating (EP) Ni-P coating on a magnesium alloy substrate. The results show that under UI, the Ni-P coating becomes smooth, compact, has refined grains and is free of cracks and pores, leading to significant improvement in the coating corrosion resistance. The crystallinity of the coating is also improved by UI, transforming from amorphous state to mixture of amorphous and nanocrystalline one.