atomic form ceramic and metal
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Catégorie :Category: nCreator TI-Nspire
Auteur Author: oONOLTZOo
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Mis en ligne Uploaded: 10/10/2024 - 09:05:15
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Shortlink : http://ti-pla.net/a4245278
Type : Classeur 3.0.1
Page(s) : 1
Taille Size: 3.11 Ko KB
Mis en ligne Uploaded: 10/10/2024 - 09:05:15
Uploadeur Uploader: oONOLTZOo (Profil)
Téléchargements Downloads: 1
Visibilité Visibility: Archive publique
Shortlink : http://ti-pla.net/a4245278
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Fichier Nspire généré sur TI-Planet.org.
Compatible OS 3.0 et ultérieurs.
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Explain, from an atomic structure point of view, whymetals can be plastically deformed to form large and complex shapes while complex ceramic parts cannot be manufactured by this technique. The ability of metals to be plastically deformed intolarge and complex shapes, while ceramics cannot, stems from fundamentaldifferences in their atomic structure and bonding characteristics .Heres a breakdown of why this occurs: 1. Atomic Bonding: Metals : In metals, the atoms are bonded by metallic bonds , which consist of a "sea of delocalized electrons" surrounding a lattice of positively charged ions. This non-directional bonding allows atoms to slide past one another without breaking the metallic bonds. As a result, metals can undergo significant plastic deformation, enabling them to be shaped and formed into complex geometries. Ceramics : Ceramics, on the other hand, are typically composed of ionic and/or covalent bonds . These bonds are strong and directional , meaning that atoms are tightly bound in specific positions. This makes it difficult for atoms to move or slip past each other under stress without breaking bonds, leading to brittle fracture rather than plastic deformation. 2. Crystal Structure and Slip Systems: Metals : Metals have relatively simple and dense crystal structures , such as body-centered cubic (BCC), face-centered cubic (FCC), and hexagonal close-packed (HCP) structures. These crystal structures have a large number of slip systems , which are specific planes and directions along which dislocations (defects in the crystal structure) can move easily. The movement of dislocations allows metals to plastically deform without fracturing. Ceramics : Ceramics have more complex crystal structures with fewer slip systems . Because of the strong ionic or covalent bonds and the fewer slip systems, dislocations in ceramics are much less mobile. This means ceramics cannot easily undergo plastic deformation; instead, they fracture when subjected to stress beyond their elastic limit. 3. Ductility vs. Brittleness: Metals : Due to the mobility of dislocations and the ability to accommodate deformation through slip, metals are ductile . They can stretch, bend, or compress without breaking, making them ideal for forming into complex shapes through processes like forging, rolling, or extrusion. Ceramics : Ceramics are brittle because their atomic structure does not allow for the same kind of dislocation movement as metals. When stress is applied, instead of deforming plastically, ceramics fracture abruptly because their strong bonds break rather than allow atomic planes to slip. 4. Defect Tolerance: Metals : Metals are relatively tolerant of defects such as dislocations or grain boundaries. These defects can move under stress and contribute to plastic deformation, which helps metals absorb and redistribute stress without failing. Ceramics : Ceramics are highly sensitive to defects such as cracks, voids, or grain boundaries. These defects concentrate stress, leading to brittle failure rather than plastic deformation, as the atomic bonds in ceramics cannot stretch or shift to accommodate strain. Conclusion: From an atomic structure perspective, the key differencesbetween metals and ceramics are their bonding and dislocation mobility. Metals have metallic bonds that allow atoms to slide past each other throughdislocation movement, making them ductile and capable of plasticdeformation. In contrast, ceramics are bonded by strong ionic orcovalent bonds, have fewer slip systems, and cannot accommodate dislocationmovement, making them brittle and unable to undergo plastic deformation.Therefore, ceramics cannot be shaped into complex parts by plastic deformationmethods like metals can. Made with nCreator - tiplanet.org
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Compatible OS 3.0 et ultérieurs.
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Explain, from an atomic structure point of view, whymetals can be plastically deformed to form large and complex shapes while complex ceramic parts cannot be manufactured by this technique. The ability of metals to be plastically deformed intolarge and complex shapes, while ceramics cannot, stems from fundamentaldifferences in their atomic structure and bonding characteristics .Heres a breakdown of why this occurs: 1. Atomic Bonding: Metals : In metals, the atoms are bonded by metallic bonds , which consist of a "sea of delocalized electrons" surrounding a lattice of positively charged ions. This non-directional bonding allows atoms to slide past one another without breaking the metallic bonds. As a result, metals can undergo significant plastic deformation, enabling them to be shaped and formed into complex geometries. Ceramics : Ceramics, on the other hand, are typically composed of ionic and/or covalent bonds . These bonds are strong and directional , meaning that atoms are tightly bound in specific positions. This makes it difficult for atoms to move or slip past each other under stress without breaking bonds, leading to brittle fracture rather than plastic deformation. 2. Crystal Structure and Slip Systems: Metals : Metals have relatively simple and dense crystal structures , such as body-centered cubic (BCC), face-centered cubic (FCC), and hexagonal close-packed (HCP) structures. These crystal structures have a large number of slip systems , which are specific planes and directions along which dislocations (defects in the crystal structure) can move easily. The movement of dislocations allows metals to plastically deform without fracturing. Ceramics : Ceramics have more complex crystal structures with fewer slip systems . Because of the strong ionic or covalent bonds and the fewer slip systems, dislocations in ceramics are much less mobile. This means ceramics cannot easily undergo plastic deformation; instead, they fracture when subjected to stress beyond their elastic limit. 3. Ductility vs. Brittleness: Metals : Due to the mobility of dislocations and the ability to accommodate deformation through slip, metals are ductile . They can stretch, bend, or compress without breaking, making them ideal for forming into complex shapes through processes like forging, rolling, or extrusion. Ceramics : Ceramics are brittle because their atomic structure does not allow for the same kind of dislocation movement as metals. When stress is applied, instead of deforming plastically, ceramics fracture abruptly because their strong bonds break rather than allow atomic planes to slip. 4. Defect Tolerance: Metals : Metals are relatively tolerant of defects such as dislocations or grain boundaries. These defects can move under stress and contribute to plastic deformation, which helps metals absorb and redistribute stress without failing. Ceramics : Ceramics are highly sensitive to defects such as cracks, voids, or grain boundaries. These defects concentrate stress, leading to brittle failure rather than plastic deformation, as the atomic bonds in ceramics cannot stretch or shift to accommodate strain. Conclusion: From an atomic structure perspective, the key differencesbetween metals and ceramics are their bonding and dislocation mobility. Metals have metallic bonds that allow atoms to slide past each other throughdislocation movement, making them ductile and capable of plasticdeformation. In contrast, ceramics are bonded by strong ionic orcovalent bonds, have fewer slip systems, and cannot accommodate dislocationmovement, making them brittle and unable to undergo plastic deformation.Therefore, ceramics cannot be shaped into complex parts by plastic deformationmethods like metals can. Made with nCreator - tiplanet.org
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