An accurate and continuous measurement of heat flux is needed in many long-term operation facilities in order to monitor and improve the life of its machinery. A thin film heat flux sensor is usually fabricated via sputtering, according to different spatial arrangements of thermocouple junctions. A novel thin film heat flux sensor was designed, fabricated, and calibrated, but the connection between the thin film and the leads could not be fixed quickly and steadily. For this purpose, in this paper a method to seamlessly integrate the leads and the thin film has been proposed to improve the sensor output signal. The sensor is capable of simultaneously measuring surface heat flux and temperature magnitude, to address the current situation of the single design of heat flux sensors. The novel thin film heat flux sensor is structured as follows: Thirty pairs of NiCr-NiSi thermocouple junctions are deposited in an annular pattern on a well-designed ceramic substrate. Over the annular thermopile, a 2000 nm-thick thermal insulator layer is deposited to create a temperature gradient across the layers. In addition, in this study a new calibration method was used to evaluate the static and dynamic properties of this novel thin film heat flux sensor. The analysis and experimental results show that the heat flux calculated from the sensor output was in good agreement with the value obtained from the pre-calibrated standard sensor. The sensitivity and response time of the novel sensor were measured at 0.06 mV/(kW/m²) and 475 ms, respectively. The heat flux measurements made with the sensor presented good repeatability. The heat-transfer coefficient of the Al₂O₃ thin film was 4.477 w/(m∙k) for the novel thin film heat flux sensor described in this paper.

During the titanium alloy milling process, high temperatures in the tool-chip contact area will affect the tool life and precision of titanium alloy machining. Therefore, it is essential to measure the temperature of the tool-chip contact area continuously. In this paper, a finite element simulation model of the milling process was established using ABAQUS2020 to obtain the highest temperature location in the tool-chip contact area when milling titanium alloy. The integration of the wire with the alumina ceramic substrate formed an integrated wire substrate. Furthermore, NiCr, NiSi, and SiO₂ films were deposited on the substrate sequentially using the DC pulsed magnetron sputtering technique. Finally, its microscopic morphology and static and dynamic performance were tested. The results show that the developed thin-film thermocouple temperature sensor has a Seebeck coefficient of 40.72 μV/°C and a dynamic response time of 0.703 ms. The application of the sensor to our titanium alloy milling experiments showed that the sensor can monitor the transient temperature in the tool-chip contact area, and its temperature measurement performance showed no detrimental effect from wearing. The effect of each milling parameter on the milling temperature was analyzed using ANOVA, and a regression model with an R-sq of 96.76% was obtained for the milling temperature.

The thin-film thermocouple (TFTC) is featured on small heat capacity and rapid response speed for transient temperature measurements under narrow space and difficult installation. Consequently, we propose a novel transient temperature testing system specifically designed for TFTC. This system features signal conditioning circuits with extended bandwidth and superior transfer speeds, a cold junction compensation method that supports customizable indexing tables, and an adaptive data filtering approach that precisely balances the smoothing of steady-state data with rapid responsiveness to transient data. This approach effectively mitigating the measurement distortion of transient temperature signals and the nonlinear phenomenon in cold junction compensation for TFTC. Utilizing NiCr/NiSi TFTC, we evaluated the system’s accuracy, demonstrating a precision range of −0.5 °C–0.25 °C within 20 °C–100 °C, and a response delay under 0.1 ms. Compared to traditional thermocouple measurement systems, our system exhibits a finer time-domain resolution. Lastly, we successfully applied this system to observe the response of TFTC under the thermal load of short-pulse laser shocks, measuring a time constant of only 1.16 ms for the TFTC. This novel transient temperature testing system provides a new approach for TFTC to achieve online dynamic measurement and online calibration, and provides technical support for TFTC measurement technology towards engineering applications.

During hole-making in carbon-fiber-reinforced polymer composites (CFRP), material anisotropy and interlaminar property mismatch can cause delamination and thermal damage. These damage modes are governed by drilling axial force and drilling temperature. However, synchronous in situ measurement of both parameters remains difficult under high-speed rotation because signal transmission and structural integration are constrained. Here, a force–temperature integrated intelligent tool holder is proposed for CFRP drilling. A pressure sensor is embedded along the tool-holder axis, and a ball-spline mechanism enables stable axial-force transmission and measurement during rotation. K-type thermocouples are arranged near the cutting edge to acquire drilling temperature in situ . Modal analysis shows a first natural frequency of 1020 Hz, avoiding structural resonance during drilling. The STM32-based data acquisition and Wi–Fi wireless transmission system achieves resolutions of 0.2 N and 0.16 ° C. Static tests show maximum relative errors of 5.52% and 2.26%. Drilling tests confirm close agreement with a table-mounted dynamometer, with a maximum peak-value errors of 3.82%. The system enables synchronous in situ monitoring of drilling axial force and drilling temperature.