Effect of ultrasonic agitation on some properties of electrodeposits

This paper reviews the effect of ultrasonic agitation of the plating solution on the grain size, hardness, internal stress, porosity and brightness of electrodeposited metals. Generally, the hardness and brightness of electrodeposits are increased by ultrasonic agitation, whereas the porosity is decreased. Results from different sources for the effect of ultrasound on internal stress are conflicting, although coatings which are codeposited with hydrogen usually have a reduced internal stress. The influence of ultrasonic vibration on deposit grain size appears to be the controlling factor in most, if not all, property changes; dehydrogenation and the codeposition of extraneous particles, however, may also be important.