Ductility of metals

CORROSION EMBRITTLEMENT. The or loss of ductility of metals due to corrosion, usually as a result oF intergranular embrittlement attack, which may not readily be visible. 

How does the electron-sea model account for the malleability and ductility of metals ... 

Briefly explain how malleability and ductility of metals are explained by metallic bonding. (8.4)... 

Solids that show considerable plastic deformation before fracture generally fail in a different way from brittle solids, discussed above. An important parameter that characterises this type of failure is the ductility of the material. Ductility is a measure of the degree of plastic deformation that can be sustained by a material at fracture. The ductility of metals can be estimated by measuring the percentage elongation of a sample after fracture, where ... 

An advantage of these composites is the increased resistance to fibre damage during composite processing which results from the intrinsic ductility of metallic fibres and the possibility of exploiting their plastic deformation for composite toughness enhancement [100]. A penalty is paid due to the relatively low thermal capability and poor chemical resistance of the metallic fibre reinforcement, limiting the application temperature and environment. 

A Figure 23.12 Gold leaf (left) and copper wire (right) demonstrate the characteristic malleability and ductility of metals, respectively. 

There are a number of processes that take advantage of the ductility of metals to change shape by plastic flow. These include ... 

The electron sea model also accounts for the malleability of metals (their capacity to be pounded into sheets) and the ductility of metals (their capacity to be drawn into wires). Since there are no localized or specific bonds in a metal, we can deform it relatively easily by forcing the metal ions to slide past one another. The electron sea easUy accommodates deformations by flowing into the new shape. 

The electron sea model accounts for the electrical conductivity, thermal conductivity, maUeabUity, and ductility of metals. 

Ceramic is a porcelainlike material that has better corrosion resistance than most metals, so ceramics are used to coat items such as turbine blades. Ceramics used to be prone to cracks due to brittleness, since ceramics lack the ductility of metals. Product improvements in this material have made major strides recently, and operating temperatures for ceramics keep rising. Various manufacturers have their own customized ceramics and their manuals and specifications should be consulted if there is a question or an overtemperature problem suspected. 

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