High-frequency ultrasonic methods for determining corrosion layer thickness of hollow metallic components
| Autor: | Hongfei Liu, Lei Zhang, Kui Yao, Shihua Wang, Shuting Chen, Hongwei Liu, Zheng Zheng Wong |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Acoustics and Ultrasonics Turbine blade business.industry 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Piezoelectricity Signal Corrosion law.invention Superalloy Metal law visual_art Nondestructive testing 0103 physical sciences visual_art.visual_art_medium Ultrasonic sensor Composite material 0210 nano-technology business 010301 acoustics |
| Zdroj: | Ultrasonics. 89:166-172 |
| ISSN: | 0041-624X |
| DOI: | 10.1016/j.ultras.2018.05.006 |
| Popis: | Corrosion in internal cavity is one of the most common problems occurs in many hollow metallic components, such as pipes containing corrosive fluids and high temperature turbines in aircraft. It is highly demanded to non-destructively detect the corrosion inside hollow components and determine the corrosion extent from the external side. In this work, we present two high-frequency ultrasonic non-destructive testing (NDT) technologies, including piezoelectric pulse-echo and laser-ultrasonic methods, for detecting corrosion of Ni superalloy from the opposite side. The determination of corrosion layer thickness below ∼100 µm has been demonstrated by both methods, in comparison with X-CT and SEM. With electron microscopic examination, it is found that with multilayer corrosion structure formed over a prolonged corrosion time, the ultrasonic NDT methods can only reliably reveal outer corrosion layer thickness because of the resulting acoustic contrast among the multiple layers due to their respective different mechanical parameters. A time-frequency signal analysis algorithm is employed to effectively enhance the high frequency ultrasonic signal contrast for the piezoelectric pulse-echo method. Finally, a blind test on a Ni superalloy turbine blade with internal corrosion is conducted with the high frequency piezoelectric pulser-receiver method. |
| Databáze: | OpenAIRE |
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