Engineering problems can be resolved:

The Welding residual stress will brings serious damage on mechanical structure. There are lots of welding parts in aerospace equipments ,such as aircraft wings, rocket shell, etc. When these parts are working under harsh environment, welding residual stress will be produced. If the stress is large enough, it will destroy the parts even the whole equipments. Detecting the residual stress accurately makes it easy to assess whetherthe parts with stress can keep on working or not and it will be helpfulto take measures to eliminate the residual stress. Figure 1 is about the residual stress and its distribution of one aviation turbine disk ,based on automatic ultrasonic scan.

Works Description:

Since the propagation speed of elastic waves in solid materials with stress depends not only on the second-order elastic constants and the density of the material, but also on the high-order elastic constants and inner stress(this performance is called Acoustic Elastic Effect). The Acoustic Elastic theory is the main theory being used to determine the stress of the material based on the ultrasonic technology, which mainly focuses on the nonlinear relationship between stress and the propagation velocity of elastic waves, especially the body waves including the transverse or longitudinal wave.

Our robot NDT system to detect residual stress in Aluminum-alloy welding is based on the propagation of critical longitudinal ultrasonic wave, which is make of special transducer ,transceiver ,temperature sensor, robot ,motion control card ,trigger device and industrial control computer, control software etc.

Main Technical Parameters :

• Detection resolution：±20MPa
• Temperature Range：-10°~40℃
• Service Life: 10 years
• Workpiece depth: 0.2~150mm
  

System features:

• Can be used widely in components with complex sharp,such as armored body, gun barrel wall, bolts, glass and ceramics, etc.
  
• Wich high precision, up to ± 20MPa.
  
• Wich high detection speed,each inspection area only 3 to 5 seconds.
  
• High technology at home and abroad.