sonochemistry

Branch of chemistry based on the properties of chemicals when subjected to high-intensity ultrasound. The ultrasound causes bubbles to form, grow, and implode. The implosion generates intense local heat and extreme pressure, but for less than a millionth of a second. Light is also emitted (sonoluminescence).

Applications include the production of amorphous metals, molten metals cooled so fast they freeze before crystals have a chance to form properly. This gives them unique electromagnetic properties and resistance to corrosion.