Ultrasonic probes for metrology are critical for the quality control of several products, such as airplane engine rotors. Currently, ultrasonic analysis is performed by means of immersion testing whereby the object to be measured is submerged in water and scanned with an ultrasonic probe to obtain morphological data. The immersion of individual objects in water is labour intensive, time-consuming, restrictive and can cause damage to valuable test objects.Herein, we report the development of a disruptive non-destructive testing technology using a novel coupling approach which utilises the unique properties of super-absorbent polymer (SAP) hydrogels. Unlike other coupling materials tested, SAP hydrogels can contain up to 99.9 % of coupling fluid while exhibiting exceptional mechanical strength and flexibility. The implementation of SAP hydrogels combines the precision of immersion testing with the mobility and ease of measurement of dry coupling techniques. An ultrasonic probe has been designed which is capable of attaching a modified tip for supporting the SAP couplant.Two-layer sedimentation polymerisation (TSLP) was developed to yield polymer hydrogels comprising various monomers, crosslink densities and compositions to yield spherical hydrogels with improved characteristics (e.g., mechanical strength, responsiveness). Spherical hydrogels prepared via TLSP showed outstanding swelling and ultrasound coupling character.Evaluation of promising high strength hydrogels enabled the synthesis of spherical high strength hydrogels by TLSP and moulding techniques. The high strength hydrogels showed excellent ultrasound coupling character, and outperformed all materials previously tested for this disruptive application, in terms of their mechanical strength.We anticipate that the materials, ideas and techniques described will lead to future non-destructive testing applications. Furthermore, the polymer synthesis techniques developed will broaden further the field of hydrogels.
| Date of Award | 2 Jul 2020 |
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| Original language | English |
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| Awarding Institution | - University Of Strathclyde
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| Sponsors | University of Strathclyde |
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| Supervisor | Peter Cormack (Supervisor) & John Liggat (Supervisor) |
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