Britannica Sources used in this answer

How does ultrasonic machining shape hard and brittle materials?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Understand the concept of sonoluminescence which is a phenomenon of turning sound into light — ultrasonics Learn how collapsing bubbles with sound can create sonoluminescence.

Ultrasonic machining (USM) shapes hard and brittle materials by utilizing high-frequency vibrations to drive abrasive particles against a workpiece.1

In this process, a machine tool shaped like the desired cavity oscillates at frequencies typically between 19,000 and 40,000 hertz. This tool vibrates within a narrow gap containing a circulating water slurry mixed with abrasive grit, such as carborundum. The rapid oscillation of the tool forces the abrasive grains to impact the surface of the material, effectively chipping away small particles to achieve the intended shape.12

This nonconventional machining method is particularly effective for materials that are difficult to process through traditional means, including glass, ceramics, germanium, and precious stones. Because the process relies on mechanical impact rather than electrical conductivity, it is suitable for both insulators and conductors. Additionally, variations such as ultrasonic drilling allow for the creation of precise holes in these fragile substances.21