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The aluminum. Aluminum alloys.
The technical evolution continues experiencing and applying new aluminum alloys,
among them most current they are those than they have as component main copper
and silicon, each one of which they include particular characteristics to him.
Beaten wings with copper, this one diminishes the beginning to him of the fusion
point, taking place from 530ºC, but it increases the burst strength and its
elastic limit, has the disadvantage of reducing its resistance to the
atmospheric agents increasing its fragility. The silicon to 12% forms an alloy
eutectic (homogenous), also diminishing the point of fusion to 575ºC but with
the advantage on the previous one to increase its resistance to the atmospheric
agents and to receive a good molding. To these alloys it is added, looking for
to them to improve certain conditions, in percentage between the 0.2 and 2%, are
these the manganese, the nickel, the titanium, the tungsten, the zinc and the
cobalt. Mouse.
Constituted by alloys of copper and zinc obtained by
simultaneous fusion; he is harder than copper and of more difficult
oxidation. Laminate able Forgeable and, the common brass have 35% of zinc, with
a yellow coloration. Of grayish white color when it has more of 50% of zinc, he
is hard and fragile. The used brass to weld contains from the 40 to 50% of zinc,
being its point of fusion lower than the one of metals to weld. The brass is
sold in the commerce in form of plates of 0.12 to 0.17 mm of thickness, in wires
whose diameters have of 0.5 to 2 mm, screws, ironworks, etc. Alpaca or white
metal. It also receives the name of nickel silver. It is formed by the alloy
from copper, nickel and zinc in proportion from the 50 to 70% of copper, 13 to
25% of nickel and 13 to 25% of zinc; its color is white Argentinean. The
combination of their so attractive color and its resistance to the corrosion
gives preference him for the architectonic works; in England they make with
alpaca the services of table, that take abbreviations E.P.N.S. The platinoide is
a white metal, made up of 60% from copper, 14% of nickel, and 24% of zinc and 1
to tungsten 2 %. |
