The Engineer’s Handbook defines "ultrasonic machining" as a mechanical material removal method used for eroding holes and cavities in brittle or hard workpieces. It makes use of an abrasive slurry, high-frequency mechanical motion and shaped tools.
Ultrasonic machining easily machines materials like hardened steel, glass, diamond, quartz, ruby and carbides, the Engineer’s Handbook explains. It effectively machines all insulating or electrical conducting materials harder than HRc 40.
Morgan State University explains that ultrasonic machining is a non-traditional mechanical method of uniform stock removal, and it is applicable to conductive and non-conductive materials. It is specifically suited for extremely hard or brittle materials. Ultrasonic machining uses medium- or high-frequency vibrations via a formed tool with the shape of the cavity to be machined. A fine abrasive slurry is combined with the tool to create accurate holes of regular and irregular shapes. A transducer is used to obtain vibration of the tool top. The process does not alter the physical, chemical and metallurgical properties of the material being machined. It is a non-chemical, non-electrical and non-thermal method.
Ultrasonic machining is also known as impact grinding, and it has been used since the 1950s, Morgan State University says. It is used to cut almost any type of material, especially in the area of ceramics where it provides greater complexity of geometry, a lower degree of surface degradation, better surface finish and higher accuracy.