Room temperature impact consolidation and its application to ceramic coatings

Aerosol deposition (AD) method

Abstract

Coating processes that are thought to utilize purely collision pressure or impact force such as the aerosol deposition (AD) method or cold spray (CS) method are attracting attention. These accelerate microparticles and ultrafine particles via a carrying gas at several hundred m/sec or more, turning them into a jet stream and colliding them with the substrate, to realize a dense coating with good adhesion just by supplying a purely mechanical energy. It is thought that fine particles of metals and ceramics are macroscopically bonded at room temperature while remaining in a nearly solid state. In fact, it has been confirmed that, with the aerosol deposition method, it is possible to form a dense ceramic thin film or a thick film having a microcrystal structure of several tens of nanometers or less at room temperature and to obtain excellent electromechanical properties. Thus, in the field of semiconductor manufacturing equipment, it has been commercialized as an important coating process. This is called "Room Temperature Impact Consolidation (RTIC)". When viewed as a powder forming process, this phenomenon is fundamentally different from a thermal spray coating and shock compaction in which raw material particles are brought into a molten or semi-molten state to obtain bonding between primary particles. In this presentation, the deposition mechanism of the AD process with the RTIC phenomenon and the importance of this phenomenon for the future of coating technology are explained.