Non –Ferrous Metals
Автор: Mtchj • Октябрь 5, 2023 • Реферат • 854 Слов (4 Страниц) • 115 Просмотры
Non –Ferrous Metals
The non-ferrous metals are usually employed in industry due to:- 1- Ease of fabrication (casting, rolling, welding and machining). 2- Resistance to corrosion.
3- Electrical and thermal conductivity.
4- Weight.
Aluminum (Al)
It is a white metal produced by electrical process from the oxide (alumina).
Melting point (660ºC)
Density (2.7 gm/cm³)
Good electrical conductivity so it is used for overhead cables. High resistance to corrosion and its non- toxicity makes so it is used for cooking utensils.
It is used in aircraft and automobile components.
Aluminum alloys
The main Al-alloys are:-
1- Duralumin
Its composition is as follows:-
Copper (Cu) % | Manganese (Mn) % | Magnesium (Mg)% | Aluminum (Al)% |
3 – 4.5 | 0.4 – 0.7 | 0.4 – o.7 | rest |
∙ It has maximum strength after heat treatment and age
hardening.
∙ It used for forging, tubes, sheets and rivets.
∙ It is used in aircraft and automobile components.
2- Y- alloy
Copper (Cu) % | Manganese (Mn) % | Nickel (Ni)% | Magnesium (Mg), silicon (si), iron(Fe) % for each | Aluminum (Al)% |
3 – 4.5 | 1.2-1.7 | 1.8-2.3 | o.6% | rest |
∙ It is mainly used for casting purposes.
∙ Has better strength than duralumin at high temperatures. So it is used in aircraft engines for cylinder heads and pistons.
3- Magnalium
It is made by melting Al with 2-10%magnesium in vacuum and then cooling it in a vacuum or under pressure of 100-200 atmospheres. It also contains about 1.75% Cu. It is used in aircraft and automobile components.
4- Hindaluim
It is an alloy of Al and Mg with very small quantity of Cr.
Copper (Cu)
It is a soft, malleable and ductile material with reddish brown appearance. Melting point (1083ºC)
Density (8.9 gm/cm³)
Good electrical conductivity, so it is used in making electrical cables and wires.
It may be casted, forged, rolled and drawn into wires.
Copper alloys
The copper alloys are classified into groups according to their major alloying elements, namely
1- brasses (Cu-Zn alloys), in which zinc (Zn) is the principal alloying metal.
2-Tin bronzes (Cu-Sn alloys), in which tin (Sn) is the principal alloying metal.
3- Aluminum bronzes.
4- Cupro-nickels.
5- Nickel-silvers.
Brass
These are alloys of copper and up to 45%Zn. They may also contain small quantities of lead, tin, nickel, iron, aluminum and manganese. There are many various types of brasses, depending on the proportion of copper and zinc.
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