What is an Alloy?
Alloy is a homogeneous mixture of two or more metals or of a metal and a non-metal mixed in a fixed proportion by mass in their molten states. Alloying is a very good method of improving the properties of a metal. We can achieve the desired properties by using this method.
Examples of Alloy
Importance of Alloys
Alloys are the combination of metals, it is a homogeneous mixture of two or more metals. An alloy may contain both metal and non metal. Alloys are made to enhance the properties of metals because pure metals can never be used for manufacturing processes in Industries.
Let’s learn the advantages of alloys:
1. Increases metal hardness: Hardness of metal is achieved by mixing one metal or nonmetal with each. Alloys have increased tensile strength as compared to the constituent elements.
2. Reduces melting point: Alloying reduces the melting point of the pure metal which is alloyed as the melting point of metal is very high.
3. Increases corrosion-resistant: Alloying increases the resistance to corrosion thus decreasing the susceptibility of metals to chemical and weather influence.
4. Change the metal color: Alloying is also done to change the original color of the metal by mixing it with other metal or non-metal.
5. Aids in the good casting of metals: Pure metals solidify when they melt and contract a bit but after they are alloyed they tend to expand during solidification which results in good casting.
List of alloys, its constituent and the uses
|Alloy Name||Alloy Composition||Alloy Uses|
|Bronze||Copper + Zinc||Sculpture, door, window frames, bushings, bearings,|
|Brass||Copper + Zinc||Decorative items, musical instruments|
|Sterling Silver||Silver + Copper||Jewellery, surgical & medical instruments, medals, coins, utensils, art|
|Bell Metal||Copper + Tin||Statue construction, bell casting|
|Coin Metal||Copper+Nickel||Used to make coins|
|Duralumin||Aluminium+Copper+Manganese||Construction of ships, aeroplane, wire, bar|
|Solder||Tin+Lead||For soldering purposes|
|Stainless Steel||Iron+Chromium_Nickel||Utensils, Manufacturing of Watches & surgical instruments|
Alloy Fun Facts
- Iron is the most widely used metal but it is never used in its pure state because it is very soft and easily stretchable when hot.
- But if iron is mixed with a small amount of carbon then it becomes hard and strong.
- When iron is mixed with nickel and chromium we get stainless steel which is hard and does not rust.
- Similarly pure gold i.e. 24 carat gold is very soft and hence is not suitable for making jewelry so it is alloyed with silver and copper to make it hard.
- Alloy of the metal mercury is called amalgam.
- Copper is a good conductor of electricity but when mixed with zinc to form brass or mixed with tin to form bronze it loses its conducting property.
- An alloy of lead and tin which is called a solder has a low melting point and is thereby used for welding electrical wires together.
Daily uses of alloys
There are numerous applications of alloys in our daily lives. Let us learn the uses of alloys:
- Ever won a Bronze medal? Medals and some musical instruments are made with the help of bronze.
- Railways, utensils, roads, airports, bridges and other construction requires steel which is an alloy.
- Alnico is used to make permanent magnets.
- To permanently join electrical components, solder is used.
- To fill tooth cavities or other medical work, amalgam, an alloy of mercury is used.
- Due to high temperature strength and superplastic properties, titanium is used extensively in the aerospace industry.
- Rose gold and sterling silver are used to make jewelleries. Sterling silver also aids in making cutlery and musical instruments.
- Brass is used to make zippers, door knobs, musical instruments, door handles, locks, decorative items.
- Being a lightweight metal, aluminium is widely used in the aerospace industry.