📌 Quick Answer
Ultrasonic machining (USM) is a non-traditional machining process that removes material from hard and brittle workpieces by means of a tool vibrating at ultrasonic frequency (about 20 kHz) while an abrasive slurry is fed into the small gap between tool and work.
The vibrating tool hammers the abrasive grains against the surface, chipping away tiny particles, so it is ideal for hard, brittle, non-conductive materials such as glass and ceramics.
🔹 Key Takeaways
- The tool vibrates at around 20 kHz with a small amplitude (10 to 40 microns).
- An abrasive slurry (often boron carbide or silicon carbide) does the actual cutting.
- It suits hard, brittle materials such as glass, ceramics, quartz and carbides.
- The process creates no heat-affected zone and applies very little force.
What Is Ultrasonic Machining?
Ultrasonic machining (USM), also called ultrasonic impact grinding, is a non-traditional machining process used to cut hard and brittle materials that are difficult to machine by conventional methods. A shaped tool vibrates at ultrasonic frequency over the workpiece while a slurry of fine abrasive particles flows through the gap. The hammering action of the abrasive removes material by micro-chipping.
Working Principle
An electrical oscillator drives a transducer that converts the high-frequency electrical signal into mechanical vibrations. A horn (concentrator) amplifies the amplitude and transmits it to the tool, which vibrates at roughly 20 kHz with an amplitude of 10 to 40 microns. The abrasive slurry between the tool and work is hammered against the surface, and the impacts chip tiny particles from the brittle workpiece, gradually reproducing the tool shape in the work.
Process Parameters and Applications
The material removal rate depends on the vibration amplitude and frequency, the abrasive grain size and hardness, the slurry concentration and the static load. Common abrasives are boron carbide, silicon carbide and aluminium oxide. USM is used to drill and shape glass, ceramics, quartz, semiconductors and hardened tool steels, to make dies, and to machine delicate non-conductive parts where heat or force must be avoided.
Frequently Asked Questions
What is ultrasonic machining?
It is a non-traditional machining process that removes material from hard, brittle workpieces using a tool vibrating at about 20 kHz together with an abrasive slurry.
Which materials can be machined by USM?
Hard and brittle materials such as glass, ceramics, quartz, silicon, carbides and hardened steels, including non-conductive materials.
What abrasives are used in ultrasonic machining?
Boron carbide, silicon carbide and aluminium oxide are common; boron carbide is the most efficient but also the most expensive.
What is the difference between ultrasonic and abrasive jet machining?
USM uses a vibrating tool to hammer an abrasive slurry against the work, while abrasive jet machining fires abrasive particles in a high-velocity gas stream. USM suits hole and cavity making in hard-brittle parts; AJM suits cutting and cleaning of thin delicate parts.