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Cobalt: Chemical element, symbol Co and atomic number 27 |
Nickel: Chemical element, symbol Ni and atomic number 28 |
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Another application of materials science is the study of [[ceramic]]s and [[glass]]es, typically the most [[Brittleness|brittle materials]] with industrial relevance. Many ceramics and glasses exhibit [[Covalent bond|covalent]] or [[Ionic bonding|ionic]]-covalent bonding with SiO<sub>2</sub> ([[Silicon dioxide|silica]]) as a fundamental building block. Ceramics – not to be confused with raw, unfired [[clay]] – are usually seen in crystalline form. The vast majority of commercial glasses contain a metal oxide fused with silica. At the high temperatures used to prepare glass, the material is a [[viscous liquid]] which solidifies into a [[Entropy (order and disorder)|disordered state]] upon [[cooling]]. Windowpanes and eyeglasses are important examples. Fibers of glass are also used for long-range telecommunication and optical transmission. Scratch resistant Corning [[Gorilla Glass]] is a well-known example of the application of materials science to drastically improve the properties of common components.
Engineering ceramics are known for their [[stiffness]] and stability under high temperatures, compression and electrical stress. [[Aluminium oxide|Alumina]], [[silicon carbide]], and [[tungsten carbide]] are made from a fine powder of their constituents in a process of [[sintering]] with a binder. [[Hot pressing]] provides higher density material. [[Chemical vapor deposition]] can place a film of a ceramic on another material. [[Cermet|Cermets]] are ceramic particles containing some metals. The wear resistance of tools is derived from [[Cemented carbide|cemented carbides]] with the metal phase of [[cobalt]] and [[nickel]] typically added to modify properties.
Ceramics can be significantly strengthened for engineering applications using the principle of [[Faber-Evans model|crack deflection]].<ref>{{Cite journal |last1=Faber |first1=K. T. |last2=Evans |first2=A. G. |date=1983-04-01 |title=Crack deflection processes—I. Theory |url=https://dx.doi.org/10.1016/0001-6160%2883%2990046-9 |journal=Acta Metallurgica |language=en |volume=31 |issue=4 |pages=565–576 |doi=10.1016/0001-6160(83)90046-9 |issn=0001-6160}}</ref> This process involves the strategic addition of second-phase particles within a ceramic matrix, optimizing their shape, size, and distribution to direct and control crack propagation. This approach enhances fracture toughness, paving the way for the creation of advanced, high-performance ceramics in various industries.<ref>{{Cite journal |last1=Faber |first1=K. T. |last2=Evans |first2=A. G. |date=1983-04-01 |title=Crack deflection processes—II. Experiment |url=https://dx.doi.org/10.1016/0001-6160%2883%2990047-0 |journal=Acta Metallurgica |language=en |volume=31 |issue=4 |pages=577–584 |doi=10.1016/0001-6160(83)90047-0 |issn=0001-6160}}</ref>
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