High temperature ultrasonic measurements of plant and components for defect detection and monitoring

Lead Research Organisation: University of the West of Scotland
Department Name: School of Science

Abstract

There are many instances where components and plant operate at elevated temperatures such as turbines, high temperature processing pipework, power generation boilers and reactors. Currently, most non-destructive testing (NDT) is carried out at lower or ambient temperature, necessitating at least partial shut-down of the process. Planned outage of plant is costly but the cost of unplanned outage due to catastrophic failure can run to millions of pounds, and can have extremely serious consequences for the safety of personnel and the public. In addition, some plant contains areas that are extremely difficult to access even during an outage meaning that the only viable approach is to use permanently installed monitoring. We propose devices and concepts to enable high temperature monitoring and inspection where it is currently impossible. This is stimulated not only by the industrial imperative, but also by major advances in knowledge and understanding of high temperature piezoelectric materials, in thick film and thin film form, operating at temperatures up to 800C. The attraction in developing high temperature sensors from these materials is that they can be robust, inexpensive and permanently installed on plant. In a novel hybrid system concept, not previously applied to high temperature inspection, we will combine these with improved non-contact ultrasonic generation techniques.
 
Description Proved potential for combining hybrid contact & non-contact approaches (laser generation & AlN tranducers).
Piezoelectric AlN thin films were reliably grown by RF sputter deposition on three commonly used engineering substrates - (EN AW 1050A, BS4659: 1971 BO1,SS316)
A sputtered metal (Al or Mo) buffer layer prevented delamination of the AlN film from carbon steel and stainless steel substrates at elevated temperatures.
Thin film transducers on stainless steel SS316 substrate, demonstrated durable and stable performance, with good resistance to multiple thermal cycles at temperatures of 400-500C, with potential to 800C.
Preliminary investigations on an integrated system with EMAT/Laser generation and AlN reception demonstrated good sensitivity (0.1 - 1MHz) with guided waves on carbon steel.
Exploitation Route The thin films on flexible substrates can be used to make high frequency ultrasonic transducers for biomedical imaging.
The high temperature thin film sensors can be used to make integrated ultrasonic sensors powered by energy harvesting. Wireless sensors can be deployed around the plant.
Sectors Aerospace, Defence and Marine,Electronics,Energy,Healthcare,Pharmaceuticals and Medical Biotechnology,Other

 
Description Thin films on flexible substrates have been used to make ultrasonic transducers for research purposes. A spin-out company Novosound has been formed and is commercialising this research work.
First Year Of Impact 2017
Sector Energy,Healthcare
Impact Types Societal,Economic