Qinnan Chen

The key bottleneck in in situ monitoring of nickel‐based superalloy hot‐section components is the lack of a reliable insulating interface for oxidative and thermomechanical extremes. Conventional ceramic insulating layers and multilayer architectures remain constrained by complex processing, interfacial mismatch, limited strain tolerance, and brittle failure. Here, we report a directly printable amorphous–nanocrystalline silicate coating that enables a robust multifunctional interface on nickel‐based superalloys without additional bonding or transition layers. During annealing, the printed silicate layer densifies, locally crystallizes, and wets the superalloy surface, producing an amorphous–nanocrystalline coating with a mechanically interlocked interface. The amorphous matrix ensures electrical insulation and oxygen‐barrier performance, while dispersed nanocrystals promote strain redistribution and crack‐path deflection. The integrated structure allows the coating to maintain stable insulation at 1100°C, achieve an adhesion strength of 90.5 N, substantially suppress high‐temperature oxidation, and remain structurally intact under strains exceeding 18,000 µε. Integrated Pt thin‐film strain sensors achieve stable strain monitoring at 1100°C, and turbine‐blade demonstration further validates the printable insulating interface for conformal integration and accurate high‐temperature sensing. The printable single‐coating strategy provides a multilayer‐free interfacial platform for robust high‐temperature sensing on superalloy components.

Semiconductor thin-film thermocouples offer significant advantages for in situ temperature monitoring in advanced engineering equipment. However, the absence of a reliable cold-junction temperature compensation methodology has constrained their practical deployment. This study proposes an in situ cold-junction compensation strategy based on a Pt thin-film resistance temperature detector (RTD), wherein the Pt thin-film RTD is conformally integrated with an ITO–In₂O₃ thin-film thermocouple via sputtering and printing processes, enabling precise acquisition of cold-junction temperature without external temperature control apparatus. The fabricated Pt thin-film RTD exhibits a coefficient of determination of 0.99995 over the temperature range from ambient to 300 °C, with a temperature coefficient of resistance of 3810.09 ppm/°C, a maximum fitting error of merely 1.02 °C, repeatability precision superior to 1.46 °C, temperature resolution better than 0.2 °C, and a long-term drift rate as low as 0.006%/h. Under simulated practical operating scenarios, the RTD demonstrates superior thermal tracking performance relative to surface-mounted thermocouples. Conformal device fabrication is further realized on the curved surface of a turbine blade, where the RTD maintains characteristics consistent with those on planar substrates, and effective compensation up to 124 °C is achieved in butane flame thermal shock experiments. This strategy overcomes the limitation of conventional compensation methods to planar substrates, furnishing a reliable solution for high-precision in situ temperature monitoring on curved structures of hot-section components via semiconductor thin-film thermocouples.

The in-situ and accurate monitoring of surface temperature and heat flux on key hot-end components (e.g., turbine blades, combustion chamber walls, thermal protection systems) is essential for assessing thermal loads, validating thermal design, and ensuring operational safety in advanced aerospace, gas turbine, and hypersonic vehicle applications. While thin-film sensors offer a promising solution due to their minimal flow disturbance and surface-conformable fabrication, existing high-temperature (＞1100 ℃) thin-film thermocouples based on PtRh alloys or ceramic materials face challenges such as high cost, output drift, brittleness, and poor adhesion. To address these limitations, this study proposes and develops a novel dual-noble-metal thin-film thermocouple based on a silver-palladium (AgPd) and platinum (Pt) material system. The design leverages the high-temperature oxidation resistance and phase stability of AgPd combined with the chemical inertness and high melting point of Pt. A optimized microcrystalline glass protective layer is applied to ensure long-term stability under extreme conditions. Systematic calibration and testing reveals that the fabricated thin-film thermocouples (TFTCs) temperature sensor operate stably up to 1100 ℃ in an oxidizing atmosphere, demonstrating a full-scale error of less than ±0.5%. Correspondingly, the thermopile-based heat flux sensors (HFSs) achieve a high measurement range up to 2.2 MW/m2 with a full-scale error better than ±0.35%. This work presents a robust and high-precision sensing solution, paving the way for advanced diagnostics and control in extreme thermal environments.

In situ temperature monitoring of ceramic matrix composites (CMCs) under extreme high-temperature conditions is critical for thermal safety management. However, existing thin-film sensors suffer from cracking and signal drift in their sensitive layers due to the spatial heterogeneity of the CMC matrix’s coefficient of thermal expansion and high-temperature interfacial degradation. Here, a multiscale synergistic regulation strategy is proposed. First, the distribution characteristics of CMC fiber volume fraction are quantified using a Weibull random field model, guiding the design of a TiB2/B2O3 gradient transition layer. Leveraging the viscoelastic transition of B2O3 within the temperature range 450–1860 °C, dynamic thermal stress dissipation is achieved, reducing interfacial shear stress by 62%. A 3D interpenetrating thermal expansion matching layer is constructed using micro/nano SiC composite powders, enhancing interfacial bonding strength to 19.7 MPa. An Al2O3 insulating layer is subsequently fabricated to improve electrical insulation. Finally, an indium tin oxide/In2O3 thermocouple-sensitive layer is deposited via Weissenberg direct writing, utilizing a polymer-derived ceramic solution as the powder solvent. The resulting sensor exhibits exceptional performance in static air at 1100 °C: thermoelectric response linearity (R2 > 0.999), a Seebeck coefficient of 168.65 μV/°C, and a low thermoelectric potential drift rate of 1.27%/h over 8 h. This study provides a theoretical foundation and technological prototype for high-precision health monitoring of hot-section components in aeroengines.