Electromagnetic ultrasonic transducer with multi-phase structure and method for efficient excitation of ultrasonic waves

Abstract

The invention relates to an electromagnetic ultrasonic transducer in a multiphase structure and an ultrasonic high-efficient excitation method by utilizing the electromagnetic ultrasonic transducer. By designing an EMAT excitation coil and a plurality of fold-line windings, the ultrasonic excitation space density can be improved, the fold-line winding is formed by multiple layers of inflection coils, by combining the current excitation staggered on the space and phase, the staggering relation is matched with the excitation phase, the ampere-turns in an excitation area can be effectively increased, the ultrasonic intensity is improved, and the high-efficient excitation and single-direction transmission of the ultrasonic can be realized. A permanent magnet is magnetized in the horizontal direction, the electronic ultrasonic transducer is suitable for the electromagnetic ultrasonic nondestructive detection of a detected article which is an iron magnetic material and based on the magnetostriction principle.

Description

technical field [0001] The invention relates to electromagnetic ultrasonic non-destructive testing, in particular to an electromagnetic ultrasonic transducer with a multi-phase structure. Background technique [0002] During the operation of natural gas pipelines, there will be defects such as corrosion and cracks, which seriously affect the safe operation of the pipelines, so the pipelines must be inspected to evaluate their safety. The detection of corrosion defects mainly uses magnetic flux leakage technology, while the detection of cracks generally uses ultrasonic testing technology. Piezoelectric ultrasonic detection requires a coupling medium, which is difficult to apply to the online detection of natural gas pipelines. [0003] Electromagnetic ultrasonic is a new technology in the field of non-destructive testing. It is attracting more and more attention due to its advantages of high precision, no need for couplant, non-contact, suitable for high temperature detectio...

AI Technical Summary

Problems solved by technology

[0004] However, its limitation is that the amount of detected surface defect information that can be extracted is discrete, and it is difficult to locate the defect position on the surface and inside of the plate and estimate its damage; especially its energy conversion efficiency is low, and high-power pulse current is required to excite , which limits the application of the technique

Images