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Materials - Coggle Diagram

- - - - Is the ability of a material to resist forces without breaking,bending,shattering or changing in any permanent way.
    - - This is the ability of a material to be permanently changed in shape.Properties associated with plasticity are:Malleability,which occurs when metals are hammered or rolled into thin sheets;and Ductilty,which is the ability of certain solid substances to undergo permanent changes in shape without breaking usually by stretching the length.
    - - This is the ability of a substance to return to its original shape or volume after it has been changed by a force.Some familiar uses of elasticity are the springs in vehicles and the rubber and air in balls.
    - - This is the resistance of a material to surface abrasio,scrathching and indentation.
    - - This is the property of a material that is hard but easily broken.
    - - This is the ability to resist repeated stress cycles and tension.
  - - - Is the ability of a material to conduct heat.Thermal conductivity is important in materials science,research,electronics,building insulation and related fields.
    - - This is the change in dimensions that ocurs with most materials as the temperature is increased or decreased.
    - - The temperature at which a material turns suddenly from solid to liquid.
  - - - This is the ability of a material to conduct electrical charge.All materials conduct electricity,but some materials allow so few electrons to get through that the current is hardly noticeable.These materials are called insulators.Other materials,which conduct current readily,are called conductors.
    - - This is the ability of a material to resist,or oppose,the transport of electrical charge in response to an external electrical field.
    - - This is the ability of a material to resist chemical attack and to withstand corrosion processes such as oxidation.
    - - This is the volume occupied by a gram-atom of an element in the solid state.
    - - This is the mass of material per unit volume(kg/m3).
- - - - Ferrous metals
        
        Ferrous metals and alloys are iron-based materials and are used in a wide variety of industrial applications.
        
        Steel
        
        Is the term used for many different alloys of iron.Each type of steel has its own distinct advantages.One of the most important industrial uses of steel is the manufacture of cars.
        
        Cast iron
        
        Contain 2 per cent or more of carbon.Cast iron is very hard and brittle,and cannot be worked.It is used mainly for castings and engines.
        
        Titanium
        
        Is a lightweight,silver-gray metal which resists sea-water and sea-air corrosion or rust.It is ductile.It unites whith nearly every material.It is used principally as an alloy in iron in aircraft and jet engines.
        
        Wrought iron
        
        Is one of the purest forms of iron in common use.It contains only a very small percentage of carbon.Wrought iron is tough,but rather soft and easily worked.
      - Non-ferrous metals
        
        Non-ferrous metals and alloys do not contain iron.They are primarily used where their differnce from ferrous metals can provide an advantage.Non-ferrous metals are much more malleable than ferrous metals and also much lighter,have a higher resistance to rust and corrosion.
        
        Aluminium
        
        Is one of the most common elements in the aerth's crust.It is light,strong and resistant to corrosion.It is a very good conductor of electricity and heat.It has a wide range of uses:cans,boats,ladders,tubing,aircraft and kitchenware.
        
        Copper
        
        Is a malleable,ductile,reddish,brown metal which can be easily beaten into shape.
        
        Brass
        
        Is a copper-based alloy,a mixture of copper and zinc.Among its main properties are resistance and durability.It is used for electrical fittings and ornaments.
        
        Lead
        
        Is soft,heavy,ductile,and it loses its shape under pressure.It is mainly used in soldering,piping and batteries.
        
        Silver
        
        Can be alloyed with copper to give sterling silver.It is malleable and ductile.
        
        Zinc
        
        Is the third most common non-ferrous metal in the earth's crust.It is used in precision die-casting and copper-based alloys.
        
        Gold and silver
        
        Have long been used as alloys rather than as pure metals.Cheaper metals are added to them to reduce the cost of gold and silver articles while keeping the appearance of the precious metals.
        
        Platinum
        
        Is a rare metal which is very valuable.Because of its resistance to corrosion,it is found naturally in its pure state or in combination with other metals.It has a high melting point and is resistant to chemical attack.It is used for jewellery and electrical contacts.It is also an important industrial catalyst.
  - - - The plastics are man-made materials that can be shaped in almost any form.They can have the hardness of steel or the softness of silk.The substances used to make plastics are called synthetic resins.Synthetic resins consists of billions of tiny invisible particles called molecules,which contains even tinier particles called atoms.Chemists picture a molecule of synthetic resin as a long chain.Each link of the chain is a group of atoms called a monomer.The chainlike molecule is called a polymer.The process by which they are made is known as polymerisation.
        
        Addition polymerisation
        
        Consists of joining together small molecules to form long chains.This is achieved by a series of addition reactions.The most common polymer is polythene,which is strong,flexible and light.Polypropylene is astrong,rigid,light polymer used in the manufacture of many articles.Polystirene is very light.It is a good heat insulator and is used in packaging.
        
        Condensation polymerisation
        
        Occurs when two molecules react to form a larger molecule leaving behind a small molecule.A condensation polymer is called polyester.It is used to make synthetic fibres.Products made from plastics are attractive,easy to use and durable.
        
        Thermoplastic materials
        
        Can be melted again and again.They melt when heated to a certain temperature but harden again as they cool.Some of the most are PVC,which is strong,transparent and flexible and used for imitation leather;nylon,used for hardware,electrical appliances;acetal,used for refrigerator and washing machine;vinylidene chloride,used for bristles,window screens and packages;polyethylene,used for making plastic articles.
        
        Thermosetting materials
        
        Cannot be melted and decompose at a high temperature.After melting they harden as heat is added.Some of the most common are bakelite,used for handles,knobs and laminates;melamine,used for electrical fittings;epoxy,used for adhesives and reinforced plastics.The difference between the two types of polymers is caused by the difference in their molecular structure.
    - - Is one of the most interesting raw materials.Natural rubber comes from the juice of a tree;synthetic rubber is made from chemicals.Rubber is elastic,waterproof and a good electrical insulator,resilient and resistant to tearing and chemicals.It becomes sticky when hot and brittle when cold.In the vulcanisation process,sulphur and other substances are added to the rubber and the mixture is then heated.The process tends to increase elasticity and resistance to heat,cold,abrasion and oxidation.Rubber is made into articles as diverse;the single most important use of rubber is for tyres.
    - - Composites are formed by combining materials to form an overall structure that is better than the sum of the individual components.They are made from two or more constituent materials with different physical or chemical properties,which remain separate and distinct within the finished structure.Besides weight savings,the most important benefits of composites include:non-corrosive,non-conductive,flexible,low maintenance,long life,design flexibility.Concrete is the most common artificial composite material and consists of coarse granular material embedded in a hard matrix of material that fills the space among the aggregate particles and glues them together.It is a very robust material,that will not compress or shatter under a large compressive force,but cannot survive tensile loading.Therefore to give the concrete the ability to resist being stretched,steel bars,which can resist stretching forces,are added to concrete to form reinforced concrete.