Murray State University School of Engineering CourseWiki
CourseWiki/Machining/Production and Nontraditional Processes

Ultrasonic Machining

A vibrating tool drives abrasive particles against hard, brittle work without requiring electrical conductivity.

Ultrasonic impact machining removes material with abrasive particles

Ultrasonic impact machining removes material with abrasive particles

A shaped tool vibrates rapidly with a small stroke, driving abrasive particles in a liquid slurry against the work. The removal energy at the work is mechanical, even though electricity powers the vibration system.

Consider this process for holes or shaped cavities in hard, brittle materials such as glass and ceramics. The work need not conduct electricity. It is generally less effective for soft, ductile materials that deform instead of breaking away under particle impacts.

No thermal HAZ does not mean a perfect surface

No thermal HAZ does not mean a perfect surface

Ultrasonic impact machining normally avoids a thermal heat-affected zone. Abrasive size, tool wear, slurry access and feature depth affect dimensional control and finish. Fine abrasive can improve the surface, but removal may be slow; edge chipping and subsurface damage remain possible in brittle work.

Distinguish this process from ultrasonic-assisted cutting, where vibration is added to another cutting or grinding process. The two names do not imply identical tooling or removal mechanisms.

Why a shaped tool does not give an exact-size copy

Abrasive particles occupy space around the tool and also wear it. The finished cavity therefore depends on the tool, abrasive action and process control, not simply on copying the tool's nominal dimensions. Bullen describes loose-abrasive ultrasonic machining.

Compare Electrical Discharge Machining and Selecting a Material-Removal Process. Safety references: Machine Hazards and Housekeeping and Chemicals and Safety Data Sheets.