An Overview of the Aerosol Deposition Method: Process Fundamentals and New Trends in Materials Applications

Ceramic materials typically have to be sintered at high temperatures, often above 1000 °C. This precludes the coating of lower-melting substrate materials, such as metals, glasses and polymers, with dense and robust thin or thick ceramic films. In addition, decomposition or uncontrolled volatilization of the ceramic components can occur at elevated temperatures. As an alternative, the Aerosol Deposition (AD) method is a spray coating process to produce dense and nanocrystalline ceramic films at room temperature directly from an initial bulk powder on almost any substrate material with no need for sintering. This great potential attracts the attention of a growing number of research groups as reflected by a rapidly growing number of publications. The objective of this review is to give a holistic overview of the AD science and technology. It describes typical process equipment and parameters and starting powder and resulting film characteristics. Special attention is given to Al2O3, TiO 2, BaTiO3 and Pb(Zr,Ti)O3, as they represent a few of the most frequently used ceramics in AD. Aerosol Deposition of many other materials are also described to demonstrate the versatility of this new technology, its ability to realize novel combinations of materials and microstructures, and its suitability for future applications. Also discussed is the current state of understanding of aerosol deposition behavior and the experimental and modeling approaches used to explain the primary aerosol deposition mechanism(s).