Investigation of high temperature electrical insulation property of MgO ceramic films and the influence of annealing process

Liu, Hao; Mao, Xiling; Cui, Jinting; Jiang, Shuwen; Zhang, Wanli

doi:10.1016/j.ceramint.2019.08.151

Cited by 24 publications

(6 citation statements)

References 25 publications

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“…To ensure the thermocouple fixation in the micro-groove, as well as insulation between the thermocouple and insert material and thermocouple protection from wear and chips, a MgO ceramic adhesive (Resbond 906, Final Advance Materials, Didenheim, France) with a maximum working temperature of 1650 • C was used. The characteristics of MgO, such as high dielectric strength, durability, malleability, quick response to temperature fluctuations, mechanical stability at high temperatures, and extremely high melting point (2852 • C), make it the preferred option for thermocouple insulation material in a multitude of temperature measurement applications [39,40].…”

Section: Embedded Thermocouple Production and Calibrationmentioning

confidence: 99%

Real-Time Cutting Temperature Measurement in Turning of AISI 1045 Steel through an Embedded Thermocouple—A Comparative Study with Infrared Thermography

Guimarães

Rosas

Fernandes³

et al. 2023

JMMP

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During machining processes, a high temperature is generated in the cutting zone due to deformation of the material and friction of the chip along the surface of the tool. This high temperature has a detrimental effect on the cutting tool, and for this reason, it is of the utmost importance to assess the cutting temperature in real time during these processes. Despite all the advances and investigation in this field, accurately measuring the cutting temperature remains a great challenge. In this sense, this work intends to contribute to solving this problem by experimentally evaluating the potential of the developed approach for embedding thermocouples into the rake face of cutting tools for measuring cutting temperature in real time during dry turning of AISI 1045 steel for different cutting parameters and comparing the obtained results with infrared thermography measurements at the exact same point. A well-defined, smooth micro-groove with good surface quality was produced by laser surface modification. Then a laser-welded K-type thermocouple was fixated in the micro-groove with a MgO ceramic adhesive, ensuring protection from wear and chips, which allowed the creation of WC-Co cutting inserts with the ability to measure cutting tool temperature with a maximum error of 0.96%. Results showed that, despite yielding the same trend, the tool temperature measured by the IR thermographic camera was always lower than the temperature measured by the K-type embedded thermocouple. The proposed embedded thermocouple method proved to be a reliable, precise, accurate, and cost-effective approach for real-time temperature measurement capable of providing useful information for cutting parameter optimization, thus allowing increased productivity and tool life.

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Section: Embedded Thermocouple Production and Calibrationmentioning

confidence: 99%

Real-Time Cutting Temperature Measurement in Turning of AISI 1045 Steel through an Embedded Thermocouple—A Comparative Study with Infrared Thermography

Guimarães

Rosas

Fernandes³

et al. 2023

JMMP

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“…At elevated temperatures, the insulation resistance of the insulating layer tends to decay exponentially, thus prompting an examination of its impact on measurement errors of the TFSGs . As shown in Figure b, the apparent resistance ( R a ) of the TFSG can be expressed by the shunt circuit law as R a = ( R s × R i )/( R s + R i ), where R s and R i denote the resistance of the sensitive layer and the insulating layer, respectively Figure c demonstrates that the thickness of the deposited insulating layer was approximately 47 μm.…”

Section: Resultsmentioning

confidence: 99%

“…47 As shown in Figure 7b, the apparent resistance (R a ) of the TFSG can be expressed by the shunt circuit law as R a = (R s × R i )/(R s + R i ), where R s and R i denote the resistance of the sensitive layer and the insulating layer, respectively. 48 Figure 7c demonstrates that the thickness of the deposited insulating layer was approximately 47 μm. In order to measure R i , two solder joints were fabricated on the insulating layer, mirroring their prior positions on the sensitive layer.…”

Section: Agpd Tfsg On Metal or Curved Substratesmentioning

confidence: 99%

All-Three-Dimensionally-Printed AgPd Thick-Film Strain Gauge with a Glass–Ceramic Protective Layer for High-Temperature Applications

Zeng,

Chen,

Zhao

et al. 2023

ACS Appl. Mater. Interfaces

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A high-temperature thin/thick-film strain gauge (TFSG) shows development prospects for in situ strain monitoring of hot-end components due to their small perturbations, no damage, and fast response. Direct ink writing (DIW) 3D printing is an emerging and facile approach for the rapid fabrication of TFSG. However, TFSGs prepared based on 3D printing with both high thermal stability and low temperature coefficient of resistance (TCR) over a wide temperature range remain a great challenge. Here, we report a AgPd TFSG with a glass–ceramic protective layer based on DIW. By encapsulating the AgPd sensitive layer and regulating the Pd content, the AgPd TFSG demonstrated a low TCR (191.6 ppm/°C) from 50 to 800 °C and ultrahigh stability (with a resistance drift rate of 0.14%/h at 800 °C). Meanwhile, the achieved specifications for strain detection included a strain sensing range of ±500 με, fast response time of 153 ms, gauge factor of 0.75 at 800 °C, and high durability of >8000 cyclic loading tests. The AgPd TFSG effectively monitors strain in superalloys and can be directly deposited onto cylindrical surfaces, demonstrating the scalability of the presented approach. This work provides a strategy to develop TFSGs for in situ sensing of complex curved surfaces in harsh environments.

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“…10. MAO coating has good electrical insulation and almost no absorption of electromagnetic waves 55 . As shown in Fig.…”

Section: Absorbing Mechanism Of Organic Composite Coatingmentioning

confidence: 99%

Preparation and properties of Mg-Nd binary alloy MAO/SiO2@α-Fe2O3 organic composite coating

Sun,

Jiang,

et al. 2024

npj Mater Degrad

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In order to make magnesium alloys better used in aviation, electronic information and other fields, it is necessary to improve their corrosion resistance and wave absorption properties. In this paper, a composite coating with corrosion resistance and wave absorption properties was prepared on magnesium alloy by micro-arc oxidation-organic coating technology. An organic absorbing coating with a thickness of about 40 μm was sprayed on the MAO coating containing Yb2O3 nanoparticles. Among them, the absorbing fillers in the organic coating are mainly SiO2 and α-Fe2O3. Three different mass ratios of SiO2 and α-Fe2O3 were set to 20%, 22.5% and 25%, respectively, to prepare three different MAO/SiO2@α-Fe2O3 organic composite coatings. The morphology, roughness, microstructure and chemical composition of the organic composite coating are characterized. The results show that after coating the organic composite coating, the roughness of the coating is significantly reduced, and the compactness and interlayer adhesion of the coating are significantly improved. The electrochemical test and SKPFM test of the organic composite coating were carried out. The results showed that with the increase of the mass ratio of SiO2 and α-Fe2O3, the corrosion resistance and stability of the organic composite coating increased, and the Volta potential also gradually moved up. The microwave absorbing properties of organic composite coatings were studied by vector network analyzer. The results show that the microwave absorbing properties of the coatings are positively correlated with the mass ratio of SiO2 and α-Fe2O3.

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Investigation of high temperature electrical insulation property of MgO ceramic films and the influence of annealing process

Cited by 24 publications

References 25 publications

Real-Time Cutting Temperature Measurement in Turning of AISI 1045 Steel through an Embedded Thermocouple—A Comparative Study with Infrared Thermography

Real-Time Cutting Temperature Measurement in Turning of AISI 1045 Steel through an Embedded Thermocouple—A Comparative Study with Infrared Thermography

All-Three-Dimensionally-Printed AgPd Thick-Film Strain Gauge with a Glass–Ceramic Protective Layer for High-Temperature Applications

Preparation and properties of Mg-Nd binary alloy MAO/SiO2@α-Fe2O3 organic composite coating

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