Causes and solutions of aluminum cracking

Causes and solutions of aluminum cracking

When we using our transducers, there are some reflections of aluminum cracking of the transducer or horn from time to time. Moreover, in the failure of aluminum cracking of the transducer, there is another phenomenon that is worthy of attention. The failure of the aluminum cracking of the transducer is often continuous, and occurs in batches, that is, the frequency of occurrence is relatively high, and the ratio is relatively large. From the user's point of view, the most intuitive understanding is that the quality of the aluminum used in the transducer is not good enough, the strength is not large enough, or the aluminum alloy parts are defective in the gold processing. But the same transducer ,have a  different life span under different working conditions.

Transducer aluminum crack is the aluminum front mass of the transducer , and a transverse crack (for 20khz NTK transducer) occurs near the horn of about 15mm to 30mm, resulting in transduction. The device is invalid. Since the position of the fracture is fixed, the problem of the production process of the aluminum alloy itself can be ruled out, that is, regardless of the quality defect of the aluminum alloy material itself. Therefore, the only reason for the aluminum crack is that the fatigue stress is too large, that is, the amplitude is too large.

When the transducer works, the amplitude is larger, the stress is larger, and the transducer is performing 20,000 times per second stretching deformation, and the material strength is greatly reduced under fatigue. Ultrasound theory also proves this. As we all know, our commonly used transducer is called a longitudinal vibration half-wavelength ultrasonic transducer, and its maximum stress point is close to the front cover of the transducer, and the maximum output point of the amplitude is at both ends. Moreover, the stress of the transducer is fatigue stress, and the fatigue stress intensity is greatly reduced with respect to the static stress of the material.

We also conducted experimental verification in the laboratory. Whether it is at no load or full load, as long as the amplitude of the transducer is larger, the aluminum front cover is more likely to crack.

How to avoid transducer aluminum crack:

1. Improve aluminum and switch to imported aluminum, such as 7075 from ALCOA, USA, or use titanium alloy.

2. Appropriately reduce the transducer output amplitude. we have toensuring that the ultrasonic horn has sufficient power (amplitude) output and that the amplitude of the transducer is within safe limits.

   We can design the ultrasonic vibration system to ensure that the ultrasonic tool head has sufficient power (amplitude) output and that the amplitude of the transducer is within a safe range.

   so when you buy the ultrasonic transducers, you have to give us your applocation information.

As we known that the amplitude (displacement) of ultrasonic vibration is one of the key indicators of ultrasonic equipment. The amplitude of the ultrasonic vibration directly represents the energy of the ultrasonic output, and also relates to the strength of the relevant material and the service life of the whole machine. Regardless of the manufacturer of the ultrasonic equipment or the user who uses the ultrasonic equipment, it is important to emphasize its importance.

The work performed by the ultrasonic vibration system on the welded workpiece is ultimately the heat generated by the workpiece, which is directly related to the welding effect. If the amplitude is too small, the welding energy is not enough, the welding place is not strong, and the place where the welding is not to be heated or ablated. If the amplitude is too large, it will cause over-welding and flow. If the mold design is unreasonable and the amplitude distribution is not uniform, the welding quality will be greatly reduced, and the airtight effect will not be achieved.

In the actual design, production, and use of ultrasonic equipment, we should always understand and detect the actual amplitude of the transducer. However, since the amplitude of the transducer is small and difficult to fix, it is difficult to directly measure the amplitude of the transducer.

So choose an Experienced ultrasonic manufacturers are necessary, we will design the whole ultrasonic system depending on your application, and give you the most suitable program.