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Osmium is a hard, brittle, blue-gray metal, and the densest stable element—about twice as dense as lead. The density of osmium is slightly greater than that of iridium ; the two are so similar (22.587 versus 22.562 g/cm 3 at 20 °C) that each was at one time considered to be the densest element.
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The ductile failure model of Lynch [17] and Popovich [18] predicted that adsorption of the liquid metal leads to the weakening of atomic bonds and nucleation of dislocations, which move under stress, pile up and work harden the solid. Also, dissolution helps in the nucleation of voids which grow under stress and cause ductile failure.
Duplex stainless steel is widely used in industry because it possesses excellent oxidation resistance, but it can have limited toughness due to its large ferritic grain size and embrittlement tendencies at temperatures ranging from 280 to 500 °C, especially at 475 °C, where spinodal decomposition of the supersaturated solid ferrite solution ...
The failure of a material is usually classified into brittle failure or ductile failure . Depending on the conditions (such as temperature, state of stress, loading rate) most materials can fail in a brittle or ductile manner or both. However, for most practical situations, a material may be classified as either brittle or ductile.
The chemical elements can be broadly divided into metals, metalloids, and nonmetals according to their shared physical and chemical properties.All elemental metals have a shiny appearance (at least when freshly polished); are good conductors of heat and electricity; form alloys with other metallic elements; and have at least one basic oxide.
Toughness is related to the area under the stress–strain curve.In order to be tough, a material must be both strong and ductile. For example, brittle materials (like ceramics) that are strong but with limited ductility are not tough; conversely, very ductile materials with low strengths are also not tough.
These mechanisms can overlap in the brittle-ductile settings. Deformation mechanisms are commonly characterized as brittle , ductile , and brittle-ductile. The driving mechanism responsible is an interplay between internal (e.g. composition, grain size and lattice-preferred orientation) and external (e.g. temperature and fluid pressure) factors.