scholarly journals Brazing Coupling Performance of Piezoelectric Waveguide Transducers for the Monitoring of High Temperature Components

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 94
Author(s):  
Jiu Hong Jia ◽  
Ze Hou Wang ◽  
Dai Feng Yao ◽  
Shan-Tung Tu

Piezoelectric waveguide transducers possess great potential for the online monitoring of high temperature critical components, in order to improve their operational safety. Due to the use of a waveguide bar, the sensory device is not susceptible to high temperature environments, which enables the long-term service of the piezoelectric transducers. However, the coupling between the waveguide bar and the high-temperature component has been proven to be the most important part of the monitoring system. In order to effectively transmit waves through the junction of the waveguide bar and the monitoring target, it is necessary to research a reliable coupling method to connect the waveguide transducers with the host structure. In the present research, the feasibility of brazing coupling for wave propagation through the junction was investigated through experiments. Piezoelectric waveguide transducers were welded using various kinds of brazing filler metals. The experimental results indicate that the coupling effects of the brazing welding depend on the filler metals. At the same time, some filler metals for the effective coupling of the transducer and the target monitoring component were identified. The brazing coupling method was verified that it can non-dispersively and effectively propagate waves into the host structure with much better reliability than the conventional dry coupling approach. Moreover, the high-temperature experimental results show that the brazing-coupled waveguide bar system can work reliably and stably in high temperatures at 300 °C for a long time. This work strives to pave a solid foundation for the application of piezoelectric waveguide transducers for the structural health monitoring of high temperature critical components.

Author(s):  
Hamid R. Ahmadi Moghaddam ◽  
Pierre Mertiny

The safety of high pressure and high temperature components is paramount, and therefore, developing effective and reliable methodologies to improve the prediction of crack propagation is an important task. The present paper describes and demonstrates a multi-physics numerical analysis approach for assessing crack propagation using a sensor device. This method employs a coupled structural-thermal-electric analysis in conjunction with a thermal-fluid-structure interaction analysis to study the structural health of a high pressure and high temperature component.


2012 ◽  
Vol 184 ◽  
pp. 122-127 ◽  
Author(s):  
Mykola Ivanchenko ◽  
Yuriy Yagodzinskyy ◽  
H. Hänninen

Two oxygen-free copper grades with purity of 99.99 % were studied by means of free decay inverted torsion pendulum at the temperature range of 90 – 300 K and frequencies of 0.5 – 2 Hz. One copper grade was oxygen free electrolytically refined copper with oxygen content of 1.2 wt. ppm. The other one was oxygen-free phosphorous-alloyed grade with oxygen content less than 5 wt. ppm and phosphorous content of 30 – 70 wt. ppm. Electrochemical hydrogen charging induces a complex internal friction peak in the studied copper grades. The observed internal friction peak has a relaxation origin with apparent activation enthalpy and pre-exponential factor for the oxygen-free grade of 0.276 ± 0.002 eV and 10-11.59 ± 0.08 s, respectively. The internal friction peak can be fitted by three broadened Debye peaks (P1, P2 and P3) with activation enthalpies and pre-exponential factors of 0.248 ± 0.003 eV and 10-11.4 ± 0.4 s; 0.297 ± 0.004 eV and 10-11.8 ± 0.2 s; 0.36 ± 0.04 eV and 10-12.7 ± 1.4 s, respectively. Phosphorous doping markedly reduces the height of the observed peak. It was also shown that prior deformation by tension suppresses high-temperature components of the complex internal friction peak. Mechanism of relaxation is presumably caused by interaction of H – H pairs (low-temperature component, peak P1), interaction of hydrogen atoms with dislocations (P2) and interaction of hydrogen with impurities (high-temperature component, peak P3). Absorption of hydrogen in the studied copper grades during electrochemical hydrogen charging was confirmed by the thermal desorption method.


Author(s):  
Terutaka Fujioka

To assess creep-fatigue life consumption in a high temperature component, strain ranges and stress relaxation histories are needed to be estimated. Inelastic finite element analysis may provide these structural responses. Performing inelastic FEA is, however, usually costly, and thus simple elastic FEA-route methods to estimate these are preferred to in some practical cases. A simple method employed in a design code for the Japanese proto-type fast breeder reactor uses an elastic follow-up factor, and is applicable for components subjected to cyclic secondary stresses. A cantilever model was employed to illustrate theoretical background for this method, and lead to a default value of three for gross elastic follow-up factor for the simplicity and conservatism. Validity of this method, however, has never been confirmed theoretically for general conditions of geometry, loading, and material properties. This paper describes characteristics of the factor based on theoretical investigations of a generally-shaped component subjected to a displacement-controlled loading. Some supporting numerical examples are shown by performing elastic-plastic FEA of a notched cylinder.


Author(s):  
M. G. Burke ◽  
M. N. Gungor ◽  
M. A. Burke

Intermetallic matrix composites are candidates for ultrahigh temperature service when light weight and high temperature strength and stiffness are required. Recent efforts to produce intermetallic matrix composites have focused on the titanium aluminide (TiAl) system with various ceramic reinforcements. In order to optimize the composition and processing of these composites it is necessary to evaluate the range of structures that can be produced in these materials and to identify the characteristics of the optimum structures. Normally, TiAl materials are difficult to process and, thus, examination of a suitable range of structures would not be feasible. However, plasma processing offers a novel method for producing composites from difficult to process component materials. By melting one or more of the component materials in a plasma and controlling deposition onto a cooled substrate, a range of structures can be produced and the method is highly suited to examining experimental composite systems. Moreover, because plasma processing involves rapid melting and very rapid cooling can be induced in the deposited composite, it is expected that processing method can avoid some of the problems, such as interfacial degradation, that are associated with the relatively long time, high temperature exposures that are induced by conventional processing methods.


Alloy Digest ◽  
1989 ◽  
Vol 38 (1) ◽  

Abstract UNS NO6455 is a nickel-chromium-molybdenum alloy with outstanding high-temperature stability as shown by high ductility and corrosion resistance even after long-time aging in the range 1200-1900 F. The alloy also has excellent resistance to stress-corrosion cracking and to oxidizing atmospheres up to 1900 F. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-367. Producer or source: Nickel and nickel alloy producers.


Alloy Digest ◽  
1987 ◽  
Vol 36 (7) ◽  

Abstract UNS No. R54620 is an alpha-beta titanium alloy. It has an excellent combination of tensile strength, creep strength, toughness and high-temperature stability that makes it suitable for service to 1050 F. It is recommended for use where high strength is required. It has outstanding advantages for long-time use at temperatures to 800 F. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-86. Producer or source: Titanium alloy mills.


2021 ◽  
pp. 115824
Author(s):  
S. Terlicka ◽  
A. Dębski ◽  
W. Gąsior ◽  
A. Fornalczyk ◽  
M. Saternus

Author(s):  
Brian E. Shannon ◽  
Carl E. Jaske ◽  
Gustavo Miranda

Statoil Tjelbergodden operates a 2,400 ton/day methanol plant in Norway. In order to assess the condition and reliability of high temperature components within the reformer, a series of advanced non-destructive examination (NDE) technologies were applied to radiant catalyst tubes, outlet pigtails, and outlet collection headers. The inspection techniques were selected and developed to provide data that could easily be used in the engineering assessment of the high-temperature components. Special focus was given to detecting and quantifying high-temperature creep damage. This paper describes the NDE techniques that were employed and provides examples of typical data obtained by using the techniques. Catalyst tubes were inspected using the H SCAN® (Figure 1) multiple sensor technology. This technique utilizes two types of ultrasonic sensors, eddy current sensors, laser measurements, and elevation location sensors in scanning each catalyst tube. The H SCAN® P-CAT™ (Figure 2) technique is applied to outlet pigtails, while the H SCAN® H-CAT™ (Figure 3) technique is applied to outlet headers.


2002 ◽  
Vol 333 (1-2) ◽  
pp. 165-169 ◽  
Author(s):  
Y.Q Zhao ◽  
H.L Qu ◽  
K.Y Zhu ◽  
H Wu ◽  
C.L Liu ◽  
...  

2000 ◽  
Vol 655 ◽  
Author(s):  
Fengyan Zhang ◽  
Sheng Teng Hsu ◽  
Jer-shen Maa ◽  
Yoshi Ono ◽  
Ying Hong ◽  
...  

AbstractIr-Ta-O composite bottom electrode has extraordinary high temperature stability. It can maintain good conductivity and integrity even after 5min annealing at 1000 °C in oxygen ambient. The thermal stability of Ir-Ta-O on different substrates has been studied. It shows that Ir-Ta-O is also very stable on Si and SiO2 substrates. No hillock formation and peelings of the bottom electrode were observed after high temperature and long time annealing in O2 ambient. SEM, TEM, XRD, and AES have been used to characterize the Ir-Ta-O film and the interfaces between Ir-Ta-O bottom electrode and Si or SiO2 substrate. The composition and conductivity changes of the electrode during oxygen ambient annealing and the interdiffusion issue will be discussed. Furthermore, Ir-Ta-O/SiO2/Si capacitor with 30Å gate oxide was fabricated and the C-V and I-V characteristics were measured to confirm the stability of Ir-Ta-O on thin gate oxide.


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