Ceramics - Incredible Refractory Materials :: Art

Ceramics - Incredible Refractory MaterialsIntroduction First we will start with the definition of refractories and ceramics. Refractories and ceramics are non-metallic materials capable of maintaining physical and chemical constancy at high temperatures. Refractories in modern practice are usually ceramic in nature, and are used in a wide variety show of primary, secondary and tertiary industries. Wherever an industrial crop involves heat in excess of 700 to 800 degrees Fahrenheit (roughly), ace will find refractory material in place, either as a lining or forming the process vessel itself. Some common process vessels using refractories are boiler combustion chambers, furnaces wish the one in the foundry, incinerators, many emission control scrubbers, rotary kilns and so on. The list is by know means exhaustive. For example, Launch Pads 39A and 39B at the Kennedy Space totality are refractory lined. The shuttles themselves are lined with ceramic tiles to protect them from the h eat of re-entry into earths atmosphere, these tiles are unique to the shuttle, but are non-metallic and heat resistant. The reservation of Refractory Materials The first step in processing ceramics is crushing of the raw materials. Crushing is usually done in a ball mill, either steamed or dry. Wet crushing is more effective because it keeps the particles together and prevents the suspension of fine particles in air. The ground particles are then mixed with additives, the functions of which are one or more of the following 1. Binder for the ceramic particles 2. Lubrication for mold release and to reduce internal friction between particles 3. Wetting agent to improve salmagundi 4. Plasticizer to make the mix more plastic and formable. 5. Various agents to control foaming and sintering. 6. De-flocculent to make ceramic-water suspension. De-flocculention changes the electrical charges on the clay particles so that they repel instead of attract each other. Next, its time to begin the casting process. The shaping process for refractories are casting plastic forming and pressing. The most common casting process is slip casting. The slip is poured into a porous mold made usually of plaster of paris. Then inverted and the remaining suspension is poured out for making grok object much like slush casting. The part is then trimmed the mold opened and the part removed. The second process of shaping ceramics is plastic forming. We pass various methods of plastic forming such as extrusion, injection molding and jiggering. Plastic forming tends to orient the layered structure of clays along the direction of material flow.