You may not have heard of it, but ultrasound can help process precision features into hard and fragile materials.
The history of ultrasonic processing can be traced back to 50 years ago, but there are relatively few practitioners today. The working principle of ultrasonic processing is to send low-frequency electrical signals to the transducer, which converts electrical energy into mechanical motion. This high-frequency, low-amplitude vibration movement is acoustically transmitted to a custom tool, usually made of steel, which experiences linear oscillations. Tool movement is usually less than 0.002 inches (0.508 mm) at a rate of approximately 20 kHz.
Ultrasonic processing can cut glass, sapphire, engineering ceramics, silicon carbide, quartz, single crystal materials, PCD, ferrite, graphite, glassy carbon, composite materials and piezoelectric ceramics.
When the tool moves, the slurry flows between the tool and the workpiece. The slurry consists of abrasive particles suspended in water or chemical solutions. Abrasives include diamond, alumina, boron carbide and silicon carbide. The selected abrasive depends on the hardness of the workpiece material. The harder the workpiece, the harder the abrasive. When the tool oscillates, it hammers the particles into the workpiece and grinds it, leaving a precise inverted image of the tool shape. Low force is applied to the crystal grains, causing microscopic fracture of the workpiece, thereby removing material. The amount of force applied depends on the tool or application. Compared with traditional processing methods, the result is a significant reduction in underground damage. In turn, this reduces the possibility of workpiece breakage that could cause equipment failure.