Researching Progress in Non-destructive Testing Interior Residual Stress of Friction Stir Welding Parts

Friction stir welding (FSW) is a new type of welding technology developing in recent years. Now researches in our domestic mainly focus on the manufacturing processes and application of friction stir welding. However, because of the lack of measurement methods and correlative equipments, research about the interior residual stress of FSW parts is almost empty, but the abroad already use their advanced neutron diffraction and synchrotron radiation equipments to test the interior residual stress of FSW parts non-destructively. So recent advances about the measurement of the interior residual stress of FSW parts within this 10 years were reviewed. In addition, the different factors that affect the measurement results were discussed. Finally, a new exploring method using short-wavelength X-ray diffraction to measure the residual stress within the materials in our country was introduced, and a prospect was made on the research direction to have accurate, efficient and economical non-destructive residual stress testing methods of the FSW parts.