Work ductility

Ductile means the ability of a metal to be drawn to form a wire, or to be worked. Ductile is the opposite of brittle. ... 

The element is a steel-white metal, it does not tarnish in air, and it is the least dense and lowest melting of the platinum group of metals. When annealed, it is soft and ductile cold-working greatly increases its strength and hardness. Palladium is attacked by nitric and sulfuric acid. 

Both zirconium hydride and zirconium metal powders compact to fairly high densities at conventional pressures. During sintering the zirconium hydride decomposes and at the temperature of decomposition, zirconium particles start to bond. Sintered zirconium is ductile and can be worked without difficulty. Pure zirconium is seldom used in reactor engineering, but the powder is used in conjunction with uranium powder to form uranium—zirconium aUoys by soHd-state diffusion. These aUoys are important in reactor design because they change less under irradiation and are more resistant to corrosion. 

Copper and nickel can be alloyed with zinc to form nickel silvers. Nickel silvers are ductile, easily formed and machined, have good corrosion resistance, can be worked to provide a range of mechanical properties, and have an attractive white color. These alloys are used for ornamental purposes, as sHverplated and uncoated tableware and flatware in the electrical iadustry as contacts, connections, and springs and as many formed and machined parts (see Electrical connectors). 

Zirconium is a hard, shiny, ductile metal, similar to stainless steel in appearance. It can be hot-worked to form slabs, rods, and rounds from arc-melted ingot. Further cold-working of zirconium with intermediate annealings produces sheet, foil, bar wire, and tubing. Physical properties are given in Table 3. 

Pure barium is a silvery-white metal, although contamination with nitrogen produces a yellowish color. The metal is relatively soft and ductile and may be worked readily. It is fairly volatile (though less so than magnesium), and this property is used to advantage in commercial production. Barium has a bcc crystal stmcture at atmospheric pressure, but undergoes soHd-state phase transformations at high pressures (2,3). Because of such transformations, barium exhibits pressure-induced superconductivity at sufftciendy low temperatures (4,5). 

E. P. Butler, and E. R. EuUer, Jr., Ductile Coating for High Toughness Ceramic Matrix Composites," unpublished work, 1992. 

The body-centered-cuhic (bcc) metals and alloys are normally classified as undesirable for low temperature construction. This class includes Fe, the martensitic steels (low carbon and the 400-series stainless steels). Mo, and Nb. If not brittle at room temperature, these materials exhibit a ductile-to-brittle transition at low temperatures. Cold working of some steels, in particular, can induce the austenite-to-martensite transition. 

Ferritic stainless contains 15 to 30 percent Cr, with low carbon content (0.1 percent). The higher chromium content improves its corrosive resistance. Type 430 is a typical example. The strength of ferritic stainless can be increased by cold working but not by heat treatment. Fairly ductile ferritic grades can be fabricated by all standard methods. They are fairly easy to machine. Welding is not a problem, although it requires skilled operators. 

Pure metals are very soft indeed, and have a high ductility. This is what, for centuries, has made them so attractive at first for jewellery and weapons, and then for other implements and structures they can be worked to the shape that you want them in furthermore, their ability to work-harden means that, after you have finished, the... 

Austenitic steels have a number of advantages over their ferritic cousins. They are tougher and more ductile. They can be formed more easily by stretching or deep drawing. Because diffusion is slower in f.c.c. iron than in b.c.c. iron, they have better creep properties. And they are non-magnetic, which makes them ideal for instruments like electron microscopes and mass spectrometers. But one drawback is that austenitic steels work harden very rapidly, which makes them rather difficult to machine. 

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