News Category Home > Industry News

New spraying method for ceramic spraying

Views : 121
Author : Pei Ze Technology
Update time : 2020-11-30 09:25:34
    For a long time, ceramic spray coatings can only be produced by sintering at temperatures above 1,000 degrees Celsius. However, a novel spraying method, powder aerosol deposition (PAD) allows them to be produced at normal room temperature. Therefore, it is very attractive for industrial applications. Under the guidance of Professor Dr.-Ing, engineering scientist Ralf Moos of Bayreuth University is working on the continuous development of this technology. In the "Advanced Materials" magazine, they showed their advantages and showed how to optimize the functional properties of ceramic membranes for high-tech applications.

 
    Converted into an aerosol, that is, a mixture of gas and solid particles, by means of a carrier gas. The aerosol is then transported into the vacuum chamber and accelerated through a nozzle to several hundred meters per second and directed onto the material to be coated.  A ceramic membrane that is made by depositing powder aerosols on porous gas-permeable electrodes, such as those required in fuel cells. Using PAD, dense ceramic membranes can be applied to very different types of materials, such as steel and glass , Silicon or even plastic. To this end, the dry ceramic powder is first  
    Upon impact, the fine ceramic particles broke. The resulting fragments are only a few nanometers in size and have a fresh, active surface. They form tightly bonded dense coatings with a thickness between 1 and 100 microns. Dr. Ing explained: "Due to its dense microstructure, the coatings have already shown excellent mechanical properties even after deposition. They are very hard and have good chemical resistance." The first author of the study, Jörg Exner, is a university The driving force of PAD research work. However, it turns out that some functional properties of the coating, especially electrical conductivity, are insufficient without further steps. However, in their new research, Bayreuth's engineering scientists are now able to report effective optimization methods. In the case of powder aerosol deposition (PAD), the crystal structure is crucial. The strong impact of ceramic particles on the material can cause structural defects in the final fragments. This not only affects conductivity, but also other functional characteristics.
    These defects can be almost completely eliminated by thermal post-treatment or so-called tempering. We have shown that the required temperature is usually much lower than conventional sintering. The way to avoid these extreme temperatures is to make PAD so attractive. Therefore, it is still correct.
    This technology has high industrial potential, especially where high-quality ceramic spray coatings are required. "Exner concluded. The type of ceramic material to be processed depends on the intended technical application: dielectric ceramics are suitable for capacitors, conductive functional ceramics are suitable for sensors, and yttrium-stabilized zirconia is used for high-temperature fuel cells.
    Even lithium-ion batteries can be produced in this way. The scientific understanding of the structure and functional properties of ceramic membranes obtained at Bayreuth University will greatly contribute to the goal of integrating high-quality coating components into complex systems in a sustainable manner. Therefore, for example, new technologies in the field of energy storage and conversion, or new technologies for environmental monitoring, will benefit greatly from powder aerosol deposition applications.