Applications of Alumina Ceramics
Alumina ceramics are ceramics comprised of alumina as the primary component and have a specific level of light transmission. Alumina ceramics have become increasingly popular in the fields of manufacturing specialized instruments, lighting technology, wireless electronic technology, optics, and high-performance computing because they possess the qualities of high temperature resistance, corrosion resistance, high insulation, and high strength of the ceramic itself, as well as the optical properties of glass and incomparable advantages of many other materials, such as low electrical conductivity.
Additionally, the alumina crystal's birefringence difference is negligible. Transparency and high infrared and visible light permeability are alumina ceramics' key characteristics. Alumina ceramics also benefit from having a high thermal conductivity and superior electrical insulation. As a result, alumina ceramics are increasingly being used in high-intensity gas discharge lamps, high-temperature infrared detection windows, and other applications.
Why Use Alumina Ceramic Additives
Dry pressing, hot die casting, and injection molding are the primary techniques for creating alumina ceramic bodies. The most common method is injection molding, which can create intricate alumina ceramics. After molding, the additional resin is released during the sintering, debinding, and degreasing processes to produce alumina ceramics. Injection molding is the technique of adding some thermosetting resin to the alumina ceramic powder.
In this article a composite additive is suggested to decrease the steps in the production process. Alumina ceramics can also be produced using direct sintering technology, however this method has clear drawbacks because it cannot go through the debinding and degreasing procedures. Organic resins are present in the body of the alumina ceramic, and their breakdown temperature is lower than the sintering temperature of alumina ceramics. These organic resins contribute to the greenhouse effect by partially entering the atmosphere at high temperatures together with gases comprising nitrogen, water, and carbon dioxide. At high temperatures, some organic resins are transformed into carbon black. The application range of the alumina ceramic is impacted by the poor light transmission of the ceramic made in this manner. As a result, this article provides an additive that is necessary in the manufacturing of alumina ceramics; the amount of the additive used is smaller than that of the prior techniques, and the prior techniques can also use less paraffin wax.
Components of Alumina Ceramic Additive
The additive is made up of three components: a dispersion, an inversion agent, and a binder. Polyvinyl alcohol, methyl cellulose, acrylic resin, and emulsified paraffin are used as binder materials. Stearic acid and polyethylene glycol are used as reverse enhancers. Tetramethylammonium hydroxide and polyacrylic acid amine are used as dispersants.
Polyvinyl alcohol (15–25%), methyl cellulose (10–15%), acrylic resin (5–5%), emulsified paraffin (20–30%), stearic acid (15–15%), polyethylene (Ethylene Glycol) (10%), polyacrylate amine (5–5%), and tetramethylammonium hydroxide (5–5%) are the ingredients in the additive that are measured by weight percentage.
The additive is mixed into the alumina ceramic powder at a rate of 5-8% by weight, and the green body is formed by injection molding. The green body is placed into an electric furnace for initial firing, which is done while degumming and degreasing are done. The initial firing temperature is controlled within the range of 900-1250 °C. The process of sintering is then completed, and the temperature is kept between 1600 and 1800 degrees Celsius. Under a microscope, the manufactured alumina ceramic exhibits a homogeneous structure and little carbon black after primary firing and sintering.
Conclusion
Adding composite additive to alumina ceramics can minimize the quantity of paraffin utilized while also lowering greenhouse gas emissions through degumming and degreasing. Furthermore, the additive can be partially recovered and reused, reducing the amount of additive utilized significantly.