posted on 2023-12-18, 19:40authored byGuochun Chen, Fuxin Zhao, Yingjun Zeng, Zhixuan Su, Lida Xu, Chenhe Shao, Chao Wu, Gonghan He, Qinnan Chen, Yang Zhao, Daoheng Sun, Zhenyin Hai
Monitoring high-temperature strain on curved components
in harsh
environments is a challenge for a wide range of applications, including
in aircraft engines, gas turbines, and hypersonic vehicles. Although
there are significant improvements in the preparation of high-temperature
piezoresistive film on planar surfaces using 3D printing methods,
there are still difficulties with poor surface compatibility and high-temperature
strain testing on curved surfaces. Herein, a conformal direct ink
writing (CDIW) system coupled with an error feedback regulation strategy
was used to fabricate high-precision, thick films on curved surfaces.
This strategy enabled the maximum amount of error in the distance
between the needle and the substrate on a curved surface to be regulated
from 155 to 4 μm. A conformal Pt thick-film strain gauge (CPTFSG)
with a room-temperature strain coefficient of 1.7 was created on a
curved metallic substrate for the first time. The resistance drift
rate at 800 °C for 1 h was 1.1%, which demonstrated the excellent
stability and oxidation resistance of the CPTFSG. High-temperature
dynamic strain tests up to 769 °C revealed that the sensor had
excellent high-temperature strain test performance. Furthermore, the
CPTFSG was conformally deposited on an aero-engine turbine blade to
perform in situ tensile and compressive strain testing at room temperature.
High-temperature strain tests were conducted at 100 and 200 °C
for 600 and 580 με, respectively, demonstrating a high
steady-state response consistent with the commercial high-temperature
strain transducer. In addition, steady-state strain tests at high
temperatures up to 496 °C were tested. The CDIW error modulation
strategy provides a highly promising approach for the high-precision
fabrication of Pt thick films on complex surfaces and driving in situ
sensing of high-temperature parameters on curved components toward
practical applications.