High-temperature Harsh Environment Research Articles

Fast and robust demodulation of temperature from sparse sapphire fiber Bragg grating spectra with machine learning

Sapphire fiber Bragg gratings (FBGs) have demonstrated their efficacy in sensing at high-temperature harsh environments owing to their elevated melting point and outstanding stability. However, due to the extremely high volume of modes supported by the clad-less sapphire fiber, the demodulation capability of the reflected spectra is hindered due to their irregular and somewhat complicated shapes. Hence, a mode-stripping or scrambling step is typically employed beforehand, albeit at the expense of sensor robustness. Additionally, conventional interrogation of sapphire FBG sensors relies on an optical spectrum analyzer due to the high sensitivity provided by the spectrum analyzer, where the long data acquisition time restricts the system from detecting instantaneous temperature variations. In this study, we present a simple sensor configuration by directly butt-coupling the sapphire FBG multi-mode lead-out fiber to a single-mode lead-in fiber, and detect its reflected spectra via a low-cost, fast, and coarsely resolved (166 pm) spectrometer. We leverage machine learning to compensate for the under-sampling of the measured FBG spectra and achieve a temperature accuracy of 0.23 °C at a high data acquisition rate of 5 kHz (limited by the spectrometer). This represents a tenfold improvement in accuracy compared to conventional peak-searching and curve-fitting methods, as well as a significant enhancement in measurement speed that enables dynamic sensing. We further assess the robustness of our sensor by attaching one side of the sensor to a vibrator and still observe good performance (0.43 °C) even under strong shaking conditions. The introduced demodulation technology opens up opportunities for the broader use of sapphire FBG sensors in noisy and high-temperature harsh environments.

Phase formation mechanism of Cr2AlC MAX phase coating: In-situ TEM characterization and atomic-scale calculations

Cr2AlC, a representative MAX phase, gains increasing attention for the excellent oxidation tolerance and corrosion resistance used in harsh high temperature and strong radiation environments. However, the lack of the phase formation mechanism has become the key bottleneck to the practical applications for Cr2AlC synthesis with high purity at low temperatures. In this work, we fabricated the amorphous Cr–Al–C coating by a hybrid magnetron sputtering/cathodic arc deposition technique, in which the in-situ heating transmission electron microscopy (TEM) was conducted in a temperature range of 25–650 ℃ to address the real-time phase transformation for Cr2AlC coating. The results demonstrated that increasing the temperature from 25 to 370 ℃ led to the structural transformation from amorphous Cr–Al–C to the crystalline Cr2Al interphases. However, the high-purity Cr2AlC MAX was distinctly formed at 500 ℃, accompanied by the diminished amorphous feature. With the further increase of temperature to 650 ℃, the decomposition of Cr2AlC to Cr7C3 impurities was observed. Similar phase evolution was also evidenced by the Ab-initio molecular dynamics calculations, where the bond energy of Cr–Cr, Cr–Al, and Cr–C played the key role in the formed crystalline stability during the heating process. The observations not only provide fundamental insight into the phase formation mechanism for high-purity Cr2AlC coatings but also offer a promising strategy to manipulate the advanced MAX phase materials with high tolerance to high-temperature oxidation and heavy ion radiations.

A Strain‐Temperature Integrated Polymer‐Derived SiCN Ceramic High Temperature Sensor with Wide‐Range and Ultra‐Short Response Time

AbstractFabricating strain sensors with high response in a wide temperature and strain range is still a challenge, especially in high temperature harsh environments. Herein, a dual‐functional sensor with cantilever beam structure is fabricated using polymer‐derived SiCN ceramics, which can be applied for temperature and stain monitor. The performance of the integrated sensor is evaluated from room temperature to 1000 °C and the related sensing mechanism is analyzed. The prepared strain sensor has ultrafast response of 60 ms in the strain range of 0–3500 µε and the maximum strain rate can reach 46 200 µε s−1. Moreover, the sensor has excellent stability and ultra‐high sensitivity under high temperature environments. Additionally, the temperature can be detected separately up to 1000 °C without any disturbance. This attractive integration sensor with competitive sensitivity, excellent stability, ultrafast response speed, and broad range, has great potential to detect temperature and strain signals for practical application in high temperature extreme environments.

Novel ceramic matrix metastructure for high-temperature radar-infrared compatible stealth: Structure-function design and manufacture

Radar and infrared compatibility stealth at high temperature is difficult to achieve due to their opposing mechanism. Meanwhile, stealth structures are required to experience thermal insulation and load-bearing performance due to the high-temperature harsh environment and high velocity thermal airflows impacts. Currently, few materials can satisfy the above demands simultaneously. Herein, a ceramic matrix lattice sandwich metastructure with high-temperature radar infrared compatibility stealth characteristics, thermal insulation, and load-bearing capacities was exploited through the crossover design of electromagnetics, mechanics, and thermodynamics. A square lattice sandwich structure was constructed through interlocking technology with the rivaling out-of-plane compressive strength. The electromagnetic wave absorption property of metastructure is designed and optimized according to the equivalent circuit model based on the electrical loss theory. The metastructure exhibits excellent −10 dB absorption bandwidth at 800 °C of 4.5–14.8 GHz. Furthermore, the metastructure achieves infrared stealth at high temperature by reducing the surface temperature (from 1150 °C to 362 °C) of objects through gradient distribution structure. The lattice sandwich metastructure proposed here is expected to aid in the creation of advanced high-temperature multifunctional stealth materials.

Effects of the thermal treatments on the optical properties of SiO2 anti-reflective coatings on sapphire windows

The SiO2 films were deposited on sapphire substrates using radio frequency (RF) magnetron sputtering to enhance the mid-wave infrared (IR) transmittance. The effects of thermal treatments by annealing and in-situ heating on the SiO2 films were investigated. After annealing at 600 °C, the surface morphology, microstructure, chemical states, and optical constants were investigated. No obvious microcracks or delamination were observed on the film surfaces, indicating excellent adhesion to the sapphire substrates. With an increase in the annealing time, gradual oxidation of Si atoms within the SiO2 thin films occurred, resulting in the release of OH groups and evaporation of moisture. The refractive index exhibited slight changes, while the extinction coefficient showed a significant reduction, thus the transmittance was improved. According to the in-situ heating tests from the annealed samples, it revealed a slight increase in average transmittance with prolonged annealing time. Finally, we assessed the performance of the annealed samples by rapid heat shock to 600 °C at a very short time, which demonstrated outstanding optical performance and heat-resistant properties. The present work supports the feasibility of applying the SiO2 films under harsh high-temperature environments.

Temperature-dependent electrical and dielectric behavior of polymer-derived SiAlCN ceramics

Polymer-derived SiAlCN ceramics as sensing materials are promising materials for wireless temperature sensors to achieve application in high-temperature harsh environments. However, limited understanding for the electric and dielectric properties of SiAlCN ceramics restricts the development of wireless sensors. Herein, the electrical and dielectric properties of polymer-derived SiAlCN ceramics pyrolyzed at different temperatures are investigated systemically. The results reveal that the electric resistance of the free-carbon phase and amorphous SiAlCN ceramic phase are comparable, however, the dielectric constant of the ceramic phase is much higher than that of the free-carbon phase. The maximum dielectric constant can reach up to 2.4E+5. Furthermore, the detailed mechanism analysis reveals that the SiAlCN ceramics with different pyrolysis temperatures all obey the same relaxation process, which is interfacial polarization and non-Debye relaxation. The deep understanding of the dielectric property of polymer-derived SiAlCN ceramics is very practical to design wireless sensors for potential applications in high-temperature and harsh environments.

Achieving broadband electromagnetic absorption at a wide temperature range up to 1273 K by metamaterial design on polymer-derived SiC-BN@CNT ceramic composites

High-temperature broadband electromagnetic wave (EMW) absorption has emerged as a forefront challenge of EMW functional materials for harsh environment applications such as aerodynamically heated parts of stealth aircraft and aero engines. Herein, an innovative strategy for broadband absorption at high temperatures is proposed by combining the microstructural design of the EMW absorption phase in the polymer-derived SiC with a periodic structure design. The metamaterial was designed on SiC-BN@CNT ceramic composites with the shape of a frustum pyramid. The experimental results reveal that SiC-BN@CNT metamaterials exhibit excellent absorption performance even under a high-temperature environment of 1273 K, in which the effective absorption bandwidth (EAB) (below −10 dB) can achieve 15.52 GHz, almost covering the whole S, C, X, and Ku bands. Moreover, the CST simulation results show that the SiC-BN@CNT metamaterials have an impressive EAB of 34.62 GHz and the average absorption intensity is remarkably high with a value of 21.07 dB (<99 % absorption) in the frequency range of 2–40 GHz. The exciting EMW attenuation capability is ascribed to favorable impedance matching, enhanced conduction loss abilities, and multiple polarization loss at high temperatures. This work provides valuable insights for the development of broadband-absorbing material in high-temperature harsh environments.

Pt/HTCC Alumina based Electronic Packaging System and Integration Processes for High Temperature Harsh Environment Applications

Electronic devices capable of operation at 500°C are required for long term Venus surface missions, as well as for in situ monitoring and control of next generation aeronautical engines. High temperature sensors and electronics can also find many applications in military, and energy and automobile industries. Various silicon carbide (SiC) sensors and electronic devices have been developed for operation at 500 °C, and a compatible packaging system is needed for long term test and deployment of these high temperature devices. High temperature co-fired ceramics (HTCC) alumina with platinum (Pt) conductor was proposed for high temperature electronic packaging. A prototype Pt/HTCC alumina packaging system including chip-level package and circuit board has been briefly reported previously for long-term electrical testing of SiC integrated circuits at 500 °C, and brief testing at much higher temperatures. HTCC alumina is an excellent dielectric material with acceptable dielectric constant and low dielectric loss over wide temperature and frequency ranges. Pt is chemically noble and can be co-fired with HTCC alumina in air ambient producing a viable electronic packaging material system for high temperature applications. This paper presents a more detailed description of this packaging system including prototype low power packages and circuit boards based on HTCC alumina and Pt metallization for 500°C and other harsh environment applications. The key technical considerations for chip-level packaging and circuit board assembly, including materials and processes for 500 °C durable wire-bonding and SiC die attach, and integration of multi-chip circuit boards, are presented. Experimental test results of this packaging approach applied to SiC integrated circuits at 500 °C and 700°C are discussed as well.

Latent fingerprints identification and ink-free printing of fluorescent lignin-derived CDs/PVA nanocomposite with multi-stimuli responsive shape memory behavior

The development and comparison of latent fingerprint (LFP) are crucial for the detection and identification of LFP. However, research on stable, clear, and no background interference’s fluorescent materials for LFP recognition are scarce. In this study, lignin-derived carbon dots (CDs) with orange red emission were synthesized and combined with polyvinyl alcohol (PVA) matrix for identification of LFP and ink-free printing. The physicochemical and microstructure of the CDs and CDs/PVA nanocomposite have been precisely elucidated by TEM, FT-IR, XPS, SEM, and TGA to verify the reaction of CDs with PVA forming hydrogen bonds. The effect of CDs on the mechanical properties of PVA nanocomposite was studied. The tensile strength and elongation at break of PVA nanocomposite were increased by 113.01 % and 175.26 %, respectively. The shape memory and fluorescence properties of CDs/PVA nanocomposite were studied under different conditions such as water, acid, alkali and heat. The fluorescence intensity of CDs/PVA nanocomposites was enhanced due to the deprotonation of CDs surface under alkaline conditions. By coating CDs/PVA solution on LFP, a stable fluorescent fingerprint with clear ridge details was formed on the composite film, and it is applied to letterpress printing and gravure printing, enabling personal identification and ink-free printing. Obviously, the nanocomposite film prepared herein has multiple functions, providing potential for the design and manufacture of advanced all-round personal information identification and encryption applications in extremely harsh high temperature and strong alkaline environments.

Fs-Laser Fabricated Miniature Fabry-Perot Interferometer in a No-Core Fiber for High-Temperature Applications.

This paper reports a fiber in-line Fabry-Perot interferometer (FPI) fabricated in a no-core fiber using the direct femtosecond laser writing technique for high-temperature sensing applications. Two in-line reflectors are directly inscribed in a no-core fiber to construct a low-finesse FPI. Fringe visibility greater than 10 dB is obtained from the reflection spectra of the fabricated no-core fiber FPIs. Temperature responses of a prototype no-core fiber FPI are characterized up to 1000 °C. The proposed configuration is compact and easy to fabricate, making it attractive for sensing applications in high-temperature harsh environments.

Outstanding piezoelectric performance of BiScO3-PbTiO3-based ceramics over a wide high-temperature region

Piezoceramics with high piezoelectric performance in a wide elevated temperature range are the best potential stocks used in advanced high-temperature piezoelectric devices. Here, novel ternary perovskite piezoceramics of (0.997-x)BiScO3-xPbTiO3-0.003Bi(Zn2/3Nb1/3)O3 (BS-xPT-BZN) are synthesized and investigated. The morphotropic phase boundary (MPB) composition of the BS-xPT-BZN system is located at x = 0.625, which exhibits a high Curie temperature (TC) of 442 °C. More excitingly, the in-situ piezoelectric coefficient (d33) of the x = 0.625 MPB sample is not only as high as 558 pC/N at 200 °C, but also has a fluctuation rate of less than ± 10 % in the ultra-wide high-temperature range of 100 ∼ 308 °C. The above excellent comprehensive high-temperature piezoelectric performance should be attributed to the synergistic effect of composition-related MPB and dispersion characteristics and thermally stable ferroelectric domain state. The results demonstrate that BS-xPT-BZN ceramics can be used as very competitive perovskite piezoelectrics to construct piezoelectric devices for applications in harsh high-temperature environments.

Effects of Temperature on the Tribological Properties of Cylinder-Liner Piston Ring Lubricated with Different Oils

As one of the important friction pairs of a diesel engine, the cylinder-liner piston ring (CL-PR) faces a harsh high-temperature working environment. To explore the mapping relationship between the friction performance of the CL-PR and the change in temperature, the reciprocating-friction and wear-testing machine was used to analyze the friction performance and lubrication performance of four kinds of lubricating oil at different temperatures (room temperature, 60 °C, 90 °C, and 120 °C) from the friction coefficient, contact resistance and surface topography. The results show that the tribological properties of the four lubricating oils show different trends with the increase in temperature. The friction coefficient of the base oil first decreases and then increases with the increase in temperature; this shows that the friction property of the base oil is improved by a certain temperature rise, and the increase in temperature promotes the formation of an oxide film and reduces the friction coefficient. While the friction coefficient of other three lubricating oils with specific application scenarios increases first and then remains stable, the wear of the friction pair is the most severe at 120 °C. The wear forms are abrasive wear and adhesive wear.

Polymer-derived SiOC reinforced with core–shell nanophase structure of ZrB2/ZrO2 for excellent and stable high-temperature microwave absorption (up to 900 °C)

Microwave absorbing materials for high-temperature harsh environments are highly desirable for aerodynamically heated parts and engine combustion induced hot spots of aircrafts. This study reports ceramic composites with excellent and stable high-temperature microwave absorption in air, which are made of polymer-derived SiOC reinforced with core–shell nanophase structure of ZrB2/ZrO2. The fabricated ceramic composites have a crystallized t-ZrO2 interface between ZrB2 and SiOC domains. The ceramic composites exhibit stable dielectric properties, which are relatively insensitive to temperature change from room temperature to 900 °C. The return loss exceeds − 10 dB, especially between 28 and 40 GHz, at the elevated temperatures. The stable high-temperature electromagnetic (EM) absorption properties are attributed to the stable dielectric and electrical properties induced by the core–shell nanophase structure of ZrB2/ZrO2. Crystallized t-ZrO2 serve as nanoscale dielectric interfaces between ZrB2 and SiOC, which are favorable for EM wave introduction for enhancing polarization loss and absorption. Existence of t-ZrO2 interface also changes the temperature-dependent DC conductivity of ZrB2/SiOC ceramic composites when compared to that of ZrB2 and SiOC alone. Experimental results from thermomechanical, jet flow, thermal shock, and water vapor tests demonstrate that the developed ceramic composites have high stability in harsh environments, and can be used as high-temperature wide-band microwave absorbing structural materials.

THERMAL MANAGEMENT STRATEGY WITH PHASE-CHANGE MATERIAL CAPSULES FOR PULSED-POWER SOURCE CONTROLLER IN EXTREME OIL-WELL THERMAL ENVIRONMENT

The application of a pulsed-power source controller provides high energy and strong penetrability, which can effectively improve the shale oil exploitation efficiency. However, the harsh high-temperature oil-well environment will significantly affect the safe operation of electronic devices. This study compares the thermal protection performance of the insulation layer with microscale phase-change material (PCM) capsules and macroscale PCM capsules composed of paraffin within a nylon shell and fabricated by 3D printing technology. Results show that the microscale PCM capsules demonstrate considerable thermal protection performance when operating under a high temperature of 100&amp;deg;C, which can prolong the operating time of the electronic device by only 64&amp;#37; in comparison to the case without the thermal protection strategy. However, the amount of PCM still shows dominant influence. On the other hand, the macroscale PCM capsules contain a relatively higher capacity of PCM, which can further extend the operating time by 84&amp;#37;, up to 92 min, within the maximum junction temperature of 80&amp;deg;C. In addition, a simplified numerical model was developed and validated with the experimental data. Eventually, the thermal protection performance of macroscale PCM capsules with orderly stacked configuration as well as the effect of thermal protection thicknesses are numerically investigated.

A new strategy to obtain thin ZrO2–Al2O3 composite aerogel coating with prominent high–temperature resistance and rapid heat dissipation

High–temperature resistant aerogel coating usually prevents damage to walls and equipment in a harsh high–temperature environment, but these coating still has some disadvantages in practical application, such as short time of high–temperature resistance or low stability. In this work, ZrO2–Al2O3 composite aerogel coating with prominent high–temperature resistance and rapid heat dissipation was successfully fabricated by employing (Al(H2PO4)3, AHP) as high–temperature adhesive to form stable phosphates products. The thermal conductivity and thermal diffusivity of the obtained ZrO2–Al2O3 composite aerogel coating are 0.1602–0.1623 ​W/mK and 0.3488–0.4702 ​mm2/s, respectively. The resultant aerogel coating with a thickness of 1.4 ​cm showed good performance in heat resistance with tolerance of flame up to ∼1300oC for 15 ​min, and rapid heat dissipation that can be cooled to 32.7–38.4oC within 60–70 ​s. Phosphate products, such as AlPO4 and ZrP2O7, are mainly formed at high temperature with the introduction of AHP, which fundamentally improves the high–temperature resistance and flame retardant of aerogel coating. Different microstructure and pore structure are responsible for the heat dissipation performance of the aerogel coating, which shows high thermal diffusivity of 0.3488–0.4702 ​mm2/s. Overall, this work provides a new strategy for preparing aerogel coating with high–temperature resistance, flame retardant, thermal stability and rapid heat dissipation suitable for harsh conditions.

Synthesis of embedded ZrC-SiC-C microspheres via carbothermal reduction for thermal stability and electromagnetic wave absorption

Development of a novel material with electromagnetic wave (EMW) absorbing capability and high-temperature resistance is a definite trend. As an ultra-high temperature ceramic, zirconium carbide (ZrC) can be used in a harsh high-temperature environment. However, ZrC has high electrical conductivity and poor low-temperature oxidation resistance. The introduction of silicon carbide (SiC) and carbon (C) into ZrC to modulate its phase composition and microstructure is a feasible method that can improve the sensitivity of ZrC to oxidizing atmospheres and electromagnetic wave absorption properties. In this study, submicron ZrC-SiC-C microspheres were successfully synthesized by the carbothermal reduction reaction combined with the template method, in which nanoscale ZrC and SiC were uniformly embedded in unreacted C. The results exhibit that nano-sized SiC and ZrC grains nucleate and grow on carbon microspheres successively, forming unique interlocking structures. The minimum reflection coefficient (RCmin) of ZrC-SiC-C microspheres attains −34.8 dB with a thickness of 1.65 mm at 13.8 GHz and the RC is below −10 dB from 12.0 to 16.0 GHz. The structure that nano-sized ZrC, SiC, and unreacted C are embedded into each other leads to dramatic increase in the heterogeneous interface, which is conducive to the loss of EMW. The incipient oxidation temperature of the ZrC-SiC-C microspheres is 411 °C, which is much higher than that of ZrC particles. The unique structure and composition increase the oxygen diffusion path and improve the oxidation resistance of ZrC. The results indicate that ZrC-SiC-C microspheres can be promisingly used as EMW absorbents in ultra-high temperature environments.

Development of Ag-In Alloy Pastes by Mechanical Alloying for Die Attachment of High-Power Semiconductor Devices.

Sintered silver paste is widely used as the die-attachment material for power semiconductors. However, sintered silver joints encounter problems, such as severe coarsening of sintered pores and oxidation issues, in harsh high-temperature environments. These lead to the deterioration of the die-attachment joints. In this paper, a novel method of sintering silver joints is demonstrated, where silver–indium alloy paste is used to improve the reliability of sintered Ag joints. The silver–indium (Ag–In) alloy paste was fabricated through mechanical alloying using the ball-milling technique. The well-bonded sintered Ag–In alloy joints inhibited pore coarsening better than pure sintered Ag joints and significantly enhanced the mechanical properties at high operating temperatures. Lastly, an oxidation mechanism for the sintered joint was proposed, and strategies to prevent such high-temperature oxidation were discussed.

Experimental Investigation on Thermal Comfort of COVID-19 Nucleic Acid Sampling Staff in Hot and Humid Environment: A Pilot Study of University Students

The current situation of Coronavirus Disease 2019 (COVID-19) prevention and control coupled with the need to work in high-temperature harsh environments makes it necessary to ensure the health and efficiency of medical staff. An experimental outdoor work tent was set up and university students were used to study the thermal comfort of personnel wearing protective clothing in hot and humid environments. The experiment was carried out simultaneously through subjective and objective field tests and physiological tests of personnel. The wet bulb globe temperature (WBGT) index was investigated to divide the outdoor thermal environment into four working conditions: 21–23 °C, 23–25 °C, 25–27 °C and 27–29 °C. Under the different thermal environment intensities, the variations of physiological parameters of test personnel were monitored. The results showed that when WBGT was increased to 27–29 °C, 100% of the participants expected the external temperature to become cooler and the humidity to decrease after one hour. When the temperature was close to 30 °C and the relative humidity was close to 60%, it was necessary to take cooling measures to reduce the thermal stress of the participants. Moreover, relationships between subjective feelings and physiological parameters of the nucleic acid sampling personnel were obtained. Results also found that the forehead, chest and back were the highest skin temperature parts, so it is most effective to give priority to improving the thermal comfort of these three locations. As an early attempt to conduct the real outdoor experimental study on the thermal comfort of COVID-19 nucleic acid sampling staff, this study provided a theoretical basis for follow-up research to develop cooling strategies for protective clothing in hot and humid outdoor environments.

A Composite Fabry-Perot Interferometric Sensor with the Dual-Cavity Structure for Simultaneous Measurement of High Temperature and Strain.

In this paper, an optical fiber composite Fabry-Perot interferometric (CFPI) sensor capable of simultaneous measurement of high temperature and strain is presented. The CFPI sensor consists of a silica-cavity intrinsic Fabry-Perot interferometer (IFPI) cascading an air-cavity extrinsic Fabry-Perot interferometer (EFPI). The IFPI is constructed at the end of the transmission single-mode fiber (SMF) by splicing a short piece of photonic crystal fiber (PCF) to SMF and then the IFPI is inserted into a quartz capillary with a reflective surface to form a single-ended sliding EFPI. In such a configuration, the IFPI is only sensitive to temperature and the EFPI is sensitive to strain, which allows the achieving of temperature-compensated strain measurement. The experimental results show that the proposed sensor has good high-temperature resistance up to 1000 °C. Strain measurement under high temperatures is demonstrated for high-temperature suitability and stable strain response. Featuring intrinsic safety, compact structure and small size, the proposed CFPI sensor may find important applications in the high-temperature harsh environment.

Silicon nitride modified enamel coatings enable high thermal shock and corrosion resistances for steel protection

Vitreous enamel is a durable inorganic material that has been extensively used in our daily life for decoration and protection of the metallic substrates. It guarantees optimal corrosion protection to the covered substrates, but, on the other side, the brittle nature of its matrix highly limits its application. Here new enamel coatings were synthesized by adding silicon nitride with the contents of 0, 1.5, 2.5, 3.5, 5, and 7.5 wt%. Scanning electron microscope (SEM), X-ray diffraction (XRD), micro indentation, impact, thermal shock, and potentiodynamic polarization tests were conducted to evaluate the microstructure and engineering properties of the studied enamel coatings. Results showed that the addition of silicon nitride leads to a high internal porosity of the enamel coating, which consequently improves the resistances against cracking under indentation and impact loads. Especially, the silicon nitride modified enamel coatings were found to survive more than 100 cycles of thermal shocks. Despite the porosity rising, the addition of silicon nitride enhanced the corrosion resistance of enamel coatings at early immersion age, and all enamel coatings kept around 10 times lower corrosion rate than that of the uncoated steel at later immersion age. The findings of this work may provide a solution to steel protection against harsh high-temperature exposure and corrosive environments.