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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.
Some nonmetals (black P, S, and Se) are brittle solids at room temperature (although each of these also have malleable, pliable or ductile allotropes). From left to right in the periodic table, the nonmetals can be divided into the reactive nonmetals and the noble gases. The reactive nonmetals near the metalloids show some incipient metallic ...
The least brittle structural ceramics are silicon carbide (mainly by virtue of its high strength) and transformation-toughened zirconia. A different philosophy is used in composite materials, where brittle glass fibers, for example, are embedded in a ductile matrix such as polyester resin. When strained, cracks are formed at the glass–matrix ...
Intermetallic compounds are generally brittle at room temperature and have high melting points. Cleavage or intergranular fracture modes are typical of intermetallics due to limited independent slip systems required for plastic deformation. However, some intermetallics have ductile fracture modes such as Nb–15Al–40Ti.
Some metals that are generally described as ductile include gold and copper, while platinum is the most ductile of all metals in pure form. [4] However, not all metals experience ductile failure as some can be characterized with brittle failure like cast iron. Polymers generally can be viewed as ductile materials as they typically allow for ...
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.
Osmium tetroxide is the most notable compound of osmium, having many uses. The name "osmium" even derives from Greek " ὀσμή, osme, 'smell'" because of the smell of osmium tetroxide. [12] It also has a number of unusual properties, one being that the solid is volatile. Its volatility, along with its strong oxidizing power, is the origin of ...
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.