Ultrasonic machining is a machining method developed in recent decades, which makes up for the shortcomings of EDM and electrochemical machining. EDM and electrochemical machining generally can only process conductive materials, not non-conductive non-metallic materials. Ultrasonic processing can not only process hard and brittle metal materials, but also is more suitable for processing non-conductive hard and brittle non-metal materials, such as glass, ceramics, and semiconductors. At the same time, ultrasonic can also be used for cleaning, welding, flaw detection, etc.

Characteristic:

Ultrasound is a part of sound waves. It can propagate in gas, liquid and solid media. However, due to its high frequency, short wavelength, and large energy, it has strong directivity during propagation, and reflection, refraction, resonance and loss are more significant. Ultrasonic waves have the properties of strong energy transmission, cavitation, reflection, transmission and refraction phenomena, interference and resonance phenomena of waves under certain conditions.

It can be seen that ultrasonic machining is a comprehensive result of mechanical impact and polishing of abrasive particles under the action of ultrasonic vibration, and ultrasonic cavitation, and the impact of abrasive particles is the main one. Since ultrasonic machining is based on local impact, it is not difficult to understand that the more brittle and harder the material, the greater the damage suffered by the impact: the easier the ultrasonic machining. On the contrary, tough materials with brittleness and low hardness are difficult to process due to its cushioning effect. According to this principle, people can choose tool materials reasonably so that they can impact abrasive grains without causing themselves to be damaged.

Features:

1) Suitable for processing various hard and brittle materials, especially non-conductive non-metallic materials. For example, glass, ceramics (alumina, silicon nitride, etc.), quartz, germanium, silicon, graphite, agate, gems, diamonds, etc. Conductive hard metal materials such as hardened steel, hard alloy, stainless steel, titanium alloy, etc. can also be processed, but the processing productivity is low.

2) Since the tool can be made into a more complex shape with a softer material, there is no need to make the tool and the workpiece perform a more complicated relative movement. Therefore, the structure of the ultrasonic processing machine tool is relatively simple, and it only needs to be pressed and fed in one direction. Easy to maintain. However, if it is necessary to process parts with a large size, a complex shape and a precise three-dimensional structure, it is still necessary to design and manufacture a three-axis CNC ultrasonic processing machine tool.

3) The removal of the processed material is based on the instantaneous local impact of extremely small abrasives, so the macroscopic cutting force on the surface of the workpiece is very small, the cutting stress and cutting heat are very small, it will not cause deformation and burns, and the surface roughness Ra value can reach 0.63~ The dimensional accuracy of 0.08μm can reach 0.01～0.02mm. It is also suitable for processing thin-walled, narrow-slit, and low-rigidity parts.

4) The geometric size of ultrasonic processing equipment is small and the equipment cost is low.

5) The area of ultrasonic processing is not large enough, and the tool head wears a lot, so the productivity is low.

6) The depth of the cylindrical hole is limited to 5 times the diameter of the tool.

7) The wear of the tool increases the rounded corners of the drilled hole, and the sharp corners become rounded corners. This means that in order to drill accurate non-through holes, it is important to replace the tools.

8) Since there are less effective abrasive particles entering the center of the tool, and the distribution of the suspension is not proper, the bottom surface of the cavity produces strong lateral vibration, so the accuracy of the processed surface is reduced. In this case, the only solution is to redesign the tool.