Optical Spinel Ceramics Processing Essay Example | Topics and Well Written Essays - 2250 words

Optical Spinel Ceramics Processing - Essay Example Alternatively, efforts to â€Å"make polycrystalline spinel by traditional hot pressing of powder have led to inhomogeneous material, typified by opaque nontransmitting regions, thereby making it unsuitable for practical applications† (Sanghera et al, 215). The properties of spinel optical ceramics can be described as follows: The composition of the material is MgAl2O4. The typical grain size of the material is bimodal in nature, 25 µm average and 150  µm averages. The structure is cubic, spinel. Lattice constant of the material is 8.082A. Density is 3.58 g/cc. It is polycrystalline in form with a melting point of 2135?C. Young’s modulus of the material is 276GPa and the sheer modulus is 18.9?106 psi. The material’s Poisson’s ratio is 0.26, and hardness of the material is 1650 Kg/mm2. Fracture toughness of the material holds a record of 1.5 MPa-m1/2 and the flexure strength is 170MPa. Specific heat of the material is 0.8191 J/g - ?C. The transition lim its are 0.25 to 6.5 microns and the thermal conductivity is 25W/m-C @25 ?C (Spinel Optical Ceramic). The present study focuses on learning about the processing of spinel optimal ceramics, including ceramic product processing, their characterization, and applications. Ceramic Product Processing: With the help of ceramic product processing, commercial products of varying sizes, shapes, details, and complexities, are produced. These products may also reflect varying compositions of their materials, structure and cost. The growing capacity to purify, expand and distinguish ceramic materials has led to application of ceramics processing into the field of science. In general, heat is applied on the material for the production of the ceramic as well as on other raw materials in order to develop a unbending product. For ceramic products that make use of naturally occurring materials like rocks and minerals, there is a need for special processing of the materials. This helps in controlling t he transparency, size of particle, distribution of the particle sizes, and heterogeneity of the materials. All these factors have a significant effect on the final product being developed, which is the finished ceramic. In case of some ceramic materials, the starting materials used for processing include powders that are prepared chemically. With the help of accurate chemical compositions and sizes of particles the synthetic materials may be used to control the production of these powders (Ceramic Processing). Once this step is achieved, the ceramic materials are transformed into particular shapes. Water and additives are added to the material for this purpose after which a shape forming process is applied on the materials. The forming techniques that are most commonly used for the purpose include extrusion, slip casting, pressing, tape casting and injection molding. Once the formation of the ceramics is complete, a green color of the ceramics would be obtained. Heat is then applied on this formed material which is a treatment referred as firing or sintering that leads to the production of a finished product rigid in nature. In some cases a glazing process is also applied, particularly where the products include electrical insulators, dinnerware and tiles. Ceramics processed for highly developed applications may undertake a machining and/or a step for polishing the materials such that they can