Magnetostrictive guided wave sensor and method for preparing magnetostrictive coating

A method for electromagnetic ultrasonic guided wave detection, comprising:

• pretreating a surface of an area to be detected of a detected object;
• and
• spraying, using a supersonic flame spraying technology, magnetostrictive alloy powder on the pretreated surface of the area to be detected to form a magnetostrictive coating attached to the pretreated surface of the area to be detected, so as to detect a defect on the area to be detected of the detected object, wherein the magnetostrictive alloy powder is Fe73.15Ga26.84(NbC)0.01 or Fe80.75Al19.24(NbC)0.01,
• wherein detecting the defect on the area to be detected of the detected object comprises:
• disposing a magnet, an exciting coil, and a receiving coil inside an encapsulation shell, and disposing the exciting coil and the receiving coil around the magnetorestrictive coating, wherein the magnet is configured to generate a bias magnetic field, and the exciting coil is configured to generate an alternating magnetic field, wherein under combined action of the bias magnetic field and the alternating magnetic field, the magnetostrictive coating generates a magnetostrictive strain which causes a particle vibration, and the vibration is transmitted in the form of waves to form ultrasonic guided waves, and wherein a signal is reflected back when the wave encounters the defect during propagation, and the signal is picked up by the receiving coil to reflect a non-destructive detection result in the form of an electrical signal.