Aleaciones no férreas utilizadas en el automóvil

Introducción

Los metales no ferreos son aquellos que no contienen hierro. Entre otros, podemos citar el aluminio, cobre, latón, bronce, etc. Actualmente gracias al continuo avance en el conocimiento de los materiales y el desarrollo de las técnicas de soldadura, pueden soldarse con éxito la mayoria de estos metales y aleaciones. En realidad, con una cierta práctica, puede adquirirse la técnica del soldeo de los metales no ferreos con tanta facilidad como la de la mayoría de los aceros.

Tipos de aleaciones no férreas

Aleaciones de aluminio

Se conocen por su baja densidad y resistencia a la corrosión, su conductividad eléctrica, su fácil fabricación y su apariencia.
La producción de aluminio en el mundo se duplico en un periodo resiente de 10 años (1967-1977). A partir de 1977, la demanda de aluminio ha disminuido, debido a la competencia de materiales cerámicos, polímetros y compuestos.
Sin embargo, la importancia del aluminio ha incrementado, gracias a su baja densidad.

Por ejemplo:
La masa de un automóvil nuevo disminuyó en un 16 % en el año 1986. Debido al decremento del 29% en aceros y al incremento del 63% en aluminio.

. Numerales Principales elementos alentes

• 1xxx Ninguno (mayor o igual que 99.00% Al)

• 2xxx Cu

• 3xxx Mn

• 4xxx Si

• 5xxx Mg

• 6xxx Mg y Si

• 7xxx Zn

• 8xxx Otros

Las reservas de aluminio son grandes, representan el 8 % de la corteza terrestre, el aluminio puede ser reciclado con facilidad.

Aleaciones de cobre

Las aleaciones de cobre, poseen diversas propiedades importantes. Sui excelente conductividad eléctrica, hace del cobre el material principal del alambrado eléctrico. Por su conductividad térmica tiene aplicaciones en radiadores e intercambiadores de calor. La estructura Fcc contribuye a su frecuente alta ductilidad y formabilidad. Su coloración se usa en acabados d diseños arquitectónicos.

El cobre de alta pureza es un material excepcionalmente blando. La adición de 2 % de peso de berilio seguido por un tratamiento térmico para producir precipitados de CuBe, es suficiente para obtener una resistencia a la tensión de mas de 10³ MPa.

Aleaciones de níquel

Níquel:

• Muy resistente a la corrosión y a la oxidación a altas temperaturas.
• Fácilmente deformable.
• Ferromagnético.

Aleaciones homogéneas(no envejecibles)

Nicrom base Ni-Cr(resistencia eléctrica elevada que no varía con la temperatura).

Inconel base Ni-Cr(muy resistente a la corrosión a alta temperatura).

Hastellow base Ni-Mo(muy resistente a los ácidos y atmósferas reductoras y oxidantes).

Aleaciones envejecibles

Inconel X(Ni-Ti-Al)

Nimonic(Ni-Cr-Ti-Al)

Conformación de los metales

Introduction

It is known that the metals are found in nature forming elements combined with other minerals. To use them as beams, to make specific parts of machines, or any other use, you must:

Insulating material accompanying elements.

Send as required in each case so that it can fulfill the mission that man throws at you.

The first goal is achieved by so-called metallurgical operations.

The metallurgy studies the processes that allow benefit minerals and metals extracted from them.

Processes of forming of metals

Comprise a varied set of operations by which changes the shape and dimensions of the metals to make those needed to adopt for each specific use. For each of these operations, the man used tools and machines.

Forming processes can be divided into major groups, which are:

1.For foundry

Consists of filling with molten metal from a vessel (mold) having a hole whose shape and dimensions are similar to those of the piece to be obtained.

This procedure can be obtained very complicated shaped parts. Metals must be used very well fluid to fill the voids of the mold.

2.Deformation hot

Consists shocks or deform by compression continued efforts a piece of metal preheated until it is the shape and precise dimensions. These processes include:

• Forge: It consists in deforming by hitting either by hand or with mechanical hammer a piece of metal heated to change its shape or dimensions. Iron and other products derived from it are forged well.

• Hot rolling:It consists of a heated metal deformed by passing between two cylinders that exert continuous pressure on him.

          The process is used for thick plates or bars certain profile. For the preparation of the thin plate in cold       

           rolling is performed.

• Hot stamping: Involves pressing between two metal molds (dies) a piece of material at the right temperature until strain filled the gap between them, taking their form which is naturally the piece to be obtained. The two prints are pressed by a powerful press.

• Hot extrusion:Consists in deforming a heated metal, forcing it to pass through a hole (row) having the shape and dimensions desired for the bar or profiles to obtain. This process is used primarily for soft metals such as zinc, copper, aluminum, etc..

3.Deformation cold

When dealing with very thin parts or materials sides, some deformation processes described above such as rolling, deformation stroke, etc. Are performed without heating the material. Among the cold deformation process can include:

• Punching: is to obtain pieces torn from a sheet by shear between a punch and a die whose shape coincides with the parts you want to retrieve.

• Drawing: This process achieves a thin sheet, how to take that force two pieces (punch and die) by pressing on it. They are used to obtain hollow metal.

4.Forming processes in metal cutting:Machining

Is to reduce the size of a piece of material and change its shape by starting up small pieces of chips using special tools provided with edge. Different metal removal processes differ mainly in the type of tools and the way it moves and the workpiece relative to one another to achieve the intended effect of metal removal. We will mention some of these processes:

• Serrated: This operation aims to chop the material: it can be done in special machines or by hand.

• The filing: Is a manual operation is performed with a tool called lime and designed to change the shape or surface condition of a small piece by starting chips tiny teeth are cut by the tool has cut in its surface.

• Chiselling: The carving is an operation which consists of starting material or separate pieces of parts of it using a tool provided with prismatic edge, which is struck at the opposite end to it with a hammer.

5.Chip boot process using machines

• Dividing up: A tool, equipped with reciprocating workpiece material starts career advancement (colored arrow). When the tool withdraws, the piece is moved to the next race in the tool find new material to cut.

• Turning: It is an operation designed to work cylindrical bodies. The clamped workpiece in the machine head rotates on its axis while the tool moves (arrow color) starts the outside material.

• Milling: A method of machining flat surfaces or of specially shaped blades by multiple tools which rotate about their axis removing material from the workpiece when it comes close.

• Drilling: This operation aims to make cylindrical holes in the pieces. A tool (drill) which is provided with helical cutting edges. The drill bit rotates about its axis and penetrate the chips tearing piece goes out through channels carved into the drill body.

6.Union of metal parts welding

This operation is solidly join two metal parts by elevating the temperature of the surfaces to be welded and providing the same or different substances to the welded nature.

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