When a metal is alloyed, it becomes inert, thereby enhancing its corrosion resistance. Alloying can be used to change the colour of the base metal. By mixing another metal or nonmetal, the alloy so formed will have a different colour. When pure metals are solidified after melting, they tend to contract a little.
However, when they are alloyed, they tend to expand on solidification. This helps to obtain good castings. Very small quantities of zinc, nickel or manganese may be added to improve the overall properties. It is harder and resistant to corrosion. Other elements may be added in smaller proportions. Brass is made to enhance the electrical properties of copper. Alnico is an alloy formed by mixing iron with nickel, cobalt and aluminium Al-Ni-Co.
It is a ferromagnetic substance and is used in permanent magnets. Solder is an alloy of tin and lead. It has a low melting point and is used to repair or join two pieces of metals.
X Request a Quote. Drop files here or Select files. Yes No. This field is for validation purposes and should be left unchanged. Still Have Questions? However, even in the strain-hardened condition, the 1xxx series alloys have very low strength when compared to the other series of aluminum alloys.
The most common applications for the 1xxx series alloys are aluminum foil, electrical buss bars, metallizing wire and chemical tanks and piping systems. The addition of alloying elements to aluminum is the principal method used to produce a selection of different materials that can be used in a wide assortment of structural applications. If we consider the seven designated aluminum alloy series used for wrought alloys, we can immediately identify the main alloying elements used for producing each of the alloy series.
I have also added some other commonly used elements and their effects on aluminum. The copper provides substantial increases in strength and facilitates precipitation hardening. The introduction of copper to aluminum can also reduce ductility and corrosion resistance. The susceptibility to solidification cracking of aluminum-copper alloys is increased; consequently, some of these alloys can be the most challenging aluminum alloys to weld. These alloys include some of the highest strength heat treatable aluminum alloys.
The most common applications for the 2xxx series alloys are aerospace, military vehicles and rocket fins. Manganese Mn 3xxx — The addition of manganese to aluminum increases strength somewhat through solution strengthening and improves strain hardening while not appreciably reducing ductility or corrosion resistance.
These are moderate strength nonheat-treatable materials that retain strength at elevated temperatures and are seldom used for major structural applications. The most common applications for the 3xxx series alloys are cooking utensils, radiators, air conditioning condensers, evaporators, heat exchangers and associated piping systems. Silicon Si 4xxx — The addition of silicon to aluminum reduces melting temperature and improves fluidity.
The alloy is harder and stronger than the pure metal. Explain why steel, which is an alloy of iron, is harder than pure iron.
Steel contains atoms of other elements as well as iron. These atoms have different sizes to iron atoms, so they distort the layers of atoms in the pure iron.
This means that a greater force is required for the layers to slide over each other in steel, so steel is harder than pure iron. Alloys An alloy is a mixture of two or more elements , where at least one element is a metal. Comparing properties of alloys and pure metals Many pure metals are too soft for many uses. Steel Elements Properties Mild steel Carbon and iron Easy to bend and pull into wires Tool steel Tungsten and iron Hard, can be heated to high temperatures Stainless steel Chromium and iron Hard, does not rust easily Explaining alloy hardness In the solid state, a pure metal has a giant metallic structure.
The metal lattice structure is distorted in alloys Question Explain why steel, which is an alloy of iron, is harder than pure iron.
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