Studies on the Platinum Thick Film Sensor Conformally Written by Laser Micro-Cladding: Formability, Microstructure,...

Area of Science:

• Materials Science
• Sensor Technology
• Surface Engineering

Background:

• High-temperature sensors require robust fabrication methods.
• Platinum (Pt) films are crucial for accurate temperature sensing.
• Existing methods like sputtering have limitations in conformal integration.

Purpose of the Study:

• To investigate laser micro-cladding (LMC) for in situ preparation of high-temperature platinum (Pt) thick film sensors.
• To systematically study the formability, microstructure, sintering, and electrical properties of LMCed Pt films.
• To evaluate the performance of LMC-fabricated Pt resistance temperature detectors (RTDs) and thermocouples.

Main Methods:

• Laser micro-cladding (LMC) was employed to deposit Pt thick films.
• Systematic analysis of film properties including adhesion, microstructure, and electrical resistivity.
• Fabrication and testing of Pt RTD and Pt-Pt10%Rh thermocouple sensors.
• Comparison with sensors fabricated via direct DC magnetron sputtering deposition.

Main Results:

• Optimal laser power density (1.37 × 10^6 W·cm^-2) yielded Pt films with minimum resistivity (46 ± 2 μΩ·cm), good adhesion, and excellent conductive networks.
• LMC-fabricated Pt RTDs exhibited high linearity (0.9985) and a TCR of 2.46 × 10^-3/°C at 920 °C.
• LMC-fabricated Pt thermocouples showed high linearity (0.9905) and a Seebeck coefficient of 9.7 μV/°C.
• Performance surpassed that of sensors made by DC magnetron sputtering.

Conclusions:

• Laser micro-cladding is a viable technique for in situ fabrication of high-performance, conformal high-temperature Pt thick film sensors.
• LMC offers advantages over traditional methods for sensor integration.
• This technology enables the development of advanced temperature sensing solutions.