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Alloy

 
8.1  Alloy
 
Definition of Alloy
A mixture of metal and other elements. 
 
Aim of Alloying
  • Increase the strength and hardness of the metal.
  • Prevent corrosion of the metal.
  • Improve the appearance of the metal.
 
Atomic Arrangement
  • An alloy is formed when foreign atoms are mixed with the pure metal.
  • These foreign atoms are different in size compared to the atoms in the pure metal.
  • Hence, the orderly arrangement of atoms in a pure metal is disrupted.
  • This makes it difficult for the layers of atoms in an alloy to slide over each other when force is applied.

The diagram shows the atomic arrangement.
 
The image is a diagram showing different types of alloys. In the center, there is a box labeled ‘ALLOY.’ Surrounding this central box are six other boxes, each connected to the center by a line. These boxes are labeled ‘Duralumin,’ ‘Bronze,’ ‘Brass,’ ‘Stainless steel,’ ‘Steel,’ and ‘Pewter.’ The background is white, and the boxes are in shades of blue. The logo ‘Pandai’ is at the bottom right corner.
 
Examples of Alloys and their Importance
Pewter
  • Is used to make souvenirs
Stainless Steel
  • Is used to make cutlery.
Steel
  • Is used to make the body of a car.
Brass
  • Is used to make keys.
Bronze
  • Is used to make medals.
Duralumin
  • Is used to make the body of an aeroplane.
 
Comparison between the Properties of an Alloy and a Pure Metal
Alloy   Pure Metal
Shiny Surface Dull
Resistant to corrosion Resistance to Corrosion Easily corroded
Hard Hardness Less hard
 
Justify the Uses of Alloys based on Their Composition and Properties
  • The uses of alloys is based on the composition and properties of the alloy produced.
  • Alloys are made for specific purposes.
  • Scientists change the elemental composition to produce alloys with different properties.
  • For example, steel and stainless steel originate from the same pure metal, which is iron. H
 
Main Components and Foreign Substances in Alloy
Stainless steel
  • Main component:
    • Iron
  • Foreign substances in alloy:
    • Chromium, nickel, carbon
Brass
  • Main component:
    • Copper
  • Foreign substances in alloy:
    • Zinc
Bronze
  • Main component:
    • Copper
  • Foreign substances in alloy:
    • Tin
Pewter
  • Main component:
    • Tin
  • Foreign substances in alloy:
    • Copper, antimony
Duralumin
  • Main component:
    • Aluminium
  • Foreign substances in alloy:
    • Copper, magnesium, manganese
 
Properties  Example
Stainless steel
  • Strong
  • Withstands corrosion
  • Shiny
  • Kitchen utensils
Brass
  • Strong
  • Shiny
  • Keys
  • Musical instruments
  • Ornaments
Bronze
  • Strong
  • Withstands corrosion
  • Hard
  • Medals
  • Statues
  • Bells
Pewter
  • Shiny and smooth surface
  • Withstands corrosion
  • Trophies
  • Picture frames
Duralumin
  • Strong
  • Withstands corrosion
  • Light
  • Body of aeroplanes
 

 

 

 

 

The views expressed in the notes here are those of the contributor and don’t necessarily represent the views of Pandai.

Alloy

 
8.1  Alloy
 
Definition of Alloy
A mixture of metal and other elements. 
 
Aim of Alloying
  • Increase the strength and hardness of the metal.
  • Prevent corrosion of the metal.
  • Improve the appearance of the metal.
 
Atomic Arrangement
  • An alloy is formed when foreign atoms are mixed with the pure metal.
  • These foreign atoms are different in size compared to the atoms in the pure metal.
  • Hence, the orderly arrangement of atoms in a pure metal is disrupted.
  • This makes it difficult for the layers of atoms in an alloy to slide over each other when force is applied.

The diagram shows the atomic arrangement.
 
The image is a diagram showing different types of alloys. In the center, there is a box labeled ‘ALLOY.’ Surrounding this central box are six other boxes, each connected to the center by a line. These boxes are labeled ‘Duralumin,’ ‘Bronze,’ ‘Brass,’ ‘Stainless steel,’ ‘Steel,’ and ‘Pewter.’ The background is white, and the boxes are in shades of blue. The logo ‘Pandai’ is at the bottom right corner.
 
Examples of Alloys and their Importance
Pewter
  • Is used to make souvenirs
Stainless Steel
  • Is used to make cutlery.
Steel
  • Is used to make the body of a car.
Brass
  • Is used to make keys.
Bronze
  • Is used to make medals.
Duralumin
  • Is used to make the body of an aeroplane.
 
Comparison between the Properties of an Alloy and a Pure Metal
Alloy   Pure Metal
Shiny Surface Dull
Resistant to corrosion Resistance to Corrosion Easily corroded
Hard Hardness Less hard
 
Justify the Uses of Alloys based on Their Composition and Properties
  • The uses of alloys is based on the composition and properties of the alloy produced.
  • Alloys are made for specific purposes.
  • Scientists change the elemental composition to produce alloys with different properties.
  • For example, steel and stainless steel originate from the same pure metal, which is iron. H
 
Main Components and Foreign Substances in Alloy
Stainless steel
  • Main component:
    • Iron
  • Foreign substances in alloy:
    • Chromium, nickel, carbon
Brass
  • Main component:
    • Copper
  • Foreign substances in alloy:
    • Zinc
Bronze
  • Main component:
    • Copper
  • Foreign substances in alloy:
    • Tin
Pewter
  • Main component:
    • Tin
  • Foreign substances in alloy:
    • Copper, antimony
Duralumin
  • Main component:
    • Aluminium
  • Foreign substances in alloy:
    • Copper, magnesium, manganese
 
Properties  Example
Stainless steel
  • Strong
  • Withstands corrosion
  • Shiny
  • Kitchen utensils
Brass
  • Strong
  • Shiny
  • Keys
  • Musical instruments
  • Ornaments
Bronze
  • Strong
  • Withstands corrosion
  • Hard
  • Medals
  • Statues
  • Bells
Pewter
  • Shiny and smooth surface
  • Withstands corrosion
  • Trophies
  • Picture frames
Duralumin
  • Strong
  • Withstands corrosion
  • Light
  • Body of aeroplanes
 

 

 

 

 

The views expressed in the notes here are those of the contributor and don’t necessarily represent the views of Pandai.
Chapter : Manufactured Substances in Industry
Topic : Alloys
Form 4 Chemistry
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