The Aerosol Deposition is a new coating method based on the mechanisms of Room Temperature Impact Consolidation where µm sized particles of the coating material are transported via carrier gas into a coating chamber. There, the particles are accelerated to several 100 m/s and sprayed onto the surface. Particles fracture due to high kinetic energy into fragments and form layer with thicknesses up to 70 µm. 

A special feature and a clear advantage of this new technology is that the coating of all material types on all substrate types is done entirely at room temperature in a low vacuum at high deposition rates (several µm/min).

While this coating technology is well established in semiconductor equipment fabrication, e.g. yttria based coatings in plasma-etch chambers, few applications are disclosed beyond this industry. In the last two years Heraeus continuously developed the aerosol deposition to optimize processes and machines for production on industrial scale and subsequently broadened the application range of the Aerosol Deposition Method.

In this contribution specifically two potential applications are presented on the field of sensing and high-temperature applications.

The first case features the production of High-Temperature Sensors. These are typically coated with a protective PVD layer to secure performance. By using aerosol deposited alpha-alumina, long term stability is improved, and measurement accuracy increased over the life span of the sensor.

The second case study deals with protective coatings for high temperature nickel alloys that are commonly used in kiln furnaces, e.g., for battery material synthesis. By using aerosol deposited alumina coatings the service life of the system parts can be extended while reducing flaking significantly.