Principle

Acoustic waves with a frequency exceeding 16000 Hz are called ultrasonic waves. Ultrasonic processing is a processing method that uses tools to vibrate at ultrasonic frequency and impact and polish the workpiece through abrasive particles. During processing, the tool acts on the workpiece with a certain pressure, the abrasive liquid is fed into the processing area, and the end face of the high-frequency vibration tool beats the abrasive particles on the surface of the workpiece, and the material in the processing area is crushed by the abrasive particles. The circulating flow of abrasive liquid takes away the pulverized material particles and keeps the abrasive particles updated. The tool gradually penetrates into the material, and the shape of the tool reappears on the workpiece.

Process characteristics and applications

(1) It is mainly suitable for processing various non-conductive hard and brittle materials, such as ceramics, glass, quartz, gems, agate, diamond, etc. It can also be processed for conductive cemented carbide and hardened steel, but the efficiency is very low.

(2) Since the relative movement between the tool and the workpiece is relatively simple during the processing, it is easy to process various complex shapes of inner surfaces and molding surfaces. Hollow shape tools can also be used to realize nesting of various shapes.

(3) During the processing process, the tool has a small macroscopic force on the processed material, and the cutting heat is smaller, and there will be no deformation and surface burns. Therefore, it is especially suitable for processing some thin walls, narrow slits, and Parts with low stiffness.

(4) Because the material is broken down by the direct action of the abrasive, the hardness of the tool material can be lower than that of the processed material, and the abrasive hardness should generally be higher than that of the processed material. Usually medium carbon steel and various shaped pipes and wires can be used as tools.

At present, in various industrial sectors, ultrasonic processing is mainly used for hole processing, nesting, cutting, engraving, and grinding of diamond wire drawing dies of hard and brittle materials. Figure 2-59 is an example of ultrasonic processing application. However, the area of ultrasonic processing is small, and the wear of the tool head is large, so the productivity is low. Generally, the diameter range of ultrasonic processing is 0.1～90mm, the depth can reach more than 100mm, and the size error of the processing hole is less than ±(0.02～0.05)mm.