Heat-Resistant Ultrasonic Sensor for High-Temperature Structural Inspection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ultrasonic sensors fail to accurately detect defects in high-temperature structural members due to thermal damage, especially when attached to curved surfaces, as they are not heat-resistant enough and require cumbersome attachment methods.
Innovation Solution
A heat-resistant ultrasonic sensor with a flexible metal plate and piezoelectric ceramics having a Curie point of 200°C or higher, attached via a metal wire mesh and thin metal film, allowing efficient ultrasonic wave transmission and reception on curved surfaces without thermal damage, and enabling attachment to high-temperature structural members during operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional ultrasonic sensors are used in high-temperature environments, then inspection of structural members can be performed, but the sensors suffer from thermal damage and cannot maintain reliable operation above 80°C
Solution Approach 1:
The patent changes the material parameters of the sensor components, specifically using piezoelectric ceramics with a Curie point of 200°C or higher instead of conventional piezoelectric materials. This parameter change enables the sensor to operate reliably at temperatures up to 250°C, resolving the contradiction between operating temperature and sensor reliability.
Solution Approach 2:
The patent employs composite material construction by combining heat-resistant piezoelectric ceramics with a flexible metal plate substrate. This composite structure provides both the high-temperature stability of ceramics and the flexibility needed for sensor operation, allowing reliable performance in high-temperature environments where conventional single-material sensors fail.
2Adaptability or versatility
If rigid ultrasonic sensors are used on curved surfaces, then the sensor structure remains simple, but the sensor cannot conform to curved surfaces and requires additional curved shoes
Solution Approach 1:
The patent replaces rigid sensor housing with a flexible metal plate that can conform to curved surfaces. The flexible plate serves as both the mounting substrate and the acoustic coupling surface, eliminating the need for separate curved shoes or adapters. This resolves the contradiction by providing curved surface adaptability while maintaining relatively simple sensor structure.
3Temperature
If epoxy adhesive is used to attach piezoelectric elements, then the attachment process is simple, but the adhesive degrades and loses bonding strength above 80°C
Solution Approach 1:
The patent replaces the degradable epoxy adhesive with a metal wire mesh that is permanently embedded in the flexible metal plate. This wire mesh provides enduring electrical and mechanical connection that does not degrade with temperature. The attachment process becomes part of the sensor manufacturing rather than a separate bonding step, resolving the contradiction between temperature resistance and ease of manufacture.
4Productivity
If periodic inspection is performed with temperature reduction, then accurate inspection can be performed, but inspection time increases and operational efficiency decreases
Solution Approach 1:
The patent enables continuous ultrasonic inspection to be performed while the structural member remains at high operating temperature. The heat-resistant piezoelectric ceramics maintain their piezoelectric properties at temperatures up to 250°C, allowing uninterrupted inspection without cooling cycles. This resolves the contradiction by maintaining both inspection efficiency through continuity and measurement precision through the stable performance of heat-resistant materials.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The sensor accurately detects defects like cracking and wall thinning on high-temperature structural members, improving inspection efficiency and reducing attachment time by maintaining electrical continuity and flexibility at elevated temperatures.
Implementation Method 1
a piezo-electric element composed of a single-crystal piezo-electric material or a composite element with a thin cylindrical piezo-electric element
Implementation Method 2
an array type ultrasonic sensor (having a plurality of piezo-electric elements) is used
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A heat-resistant ultrasonic sensor forms a piezo-electric ceramics film 3 with a thickness of 0.5 mm or smaller and a Curie point of 200°C or higher on a flexible metal plate 2. A thin metal film that is an electrode 4 is attached to a top surface of the piezo-electric ceramics film and a metal wire mesh 5 covers the thin metal film 4 and is attached to a top surface of the thin metal film 4. A core of a heat-resistant coaxial cable 7 is connected to the metal wire mesh at a connection point. The heat-resistant coaxial cable 7 is fixed to the thin metal plate 2 with a metal fixing member 8 that is a ground portion. An electric insulating cover 10 is attached to the thin metal plate 2 and covers the piezo-electric ceramics film 3, the thin metal film 4, the metal wire mesh 5, the connection point 6, the fixing member 8, and the core 9 of the coaxial cable 7. A defect of a structural member of a plant can be accurately detected by the heat-resistant ultrasonic sensor when the plant is in operation.