Metal-based sandwich type thick-film platinum resistance temperature detector for in-situ temperature monitoring of hot-end components

High-temperature resistance temperature detectors (RTDs) are gaining significant attention for various promising applications, including aeroengines, steel metallurgy, and construction machinery. However, it remains a critical challenge in developing RTDs on curved metal substrates without involving high-cost and complicated manufacturing processes. Herein, a metal-based sandwich type thick-film platinum (Pt) RTD for in-situ temperature monitoring of hot-end components is developed through a facile and high-efficient tape mask process and direct ink writing (DIW) technology. The liquid-formed glass–ceramic insulating layer and protective layer effectively immobilize the Pt particles within a sandwich structure, resulting in adequate protection from volatilization and aggregation of the Pt sensitive layer. Meanwhile, the insulating/protective layer exhibits outstanding insulation performance. Additionally, the fabricated Pt RTD achieved excellent repeatability, ultra-high stability (with a temperature drift rate of 0.7%/h at 800 °C), and high accuracy (0.92% full-scale) in the range of 50–800 °C. As an application example, the Pt RTD was fabricated on the surface of a turbine blade to verify its functionality at temperatures up to 800 °C. The exceptional performance and flexible fabrication process indicate that the Pt RTD is a promising candidate for in-situ temperature monitoring of critical aeroengine components.