On the use of conical radio frequency inductively coupled plasma torch in plasma assisted aerosol deposition

The development of advanced thin film coatings is crucial for enhancing the performance and durability of materials in various high-tech applications. Plasma-Assisted Aerosol Deposition (PAD) is an emerging coating technique that has gained significant attention from researchers due to its ability to combine the advantages of both plasma spray and aerosol deposition methods. This approach enables the production of thin, dense coatings while maintaining the original phase of the raw material, avoiding unwanted phase transitions. In this study, an industrial-scale conical radio frequency inductively coupled plasma (RF-ICP) torch connected to a vacuum chamber is utilized to deposit a thin alpha-alumina coating at low pressure. The deposition is characterized by analyzing the phase structure and coating thickness. Additionally, the effects of key parameters, including input power and plasma flow characteristics, on coating quality, efficiency, and thickness are systematically investigated. The PAD technique exhibits a promising capacity to generate thin alumina coatings characterized by suitable adhesion and density, while circumventing the phase transitions commonly encountered in traditional plasma processes.