METALS

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METALS

• Learning Objectives
• What is METAL?
• Different Types of Metals Ferrous, Non-Ferrous,
  Alloys
• Main focus of Ferrous Metals
• Properties of Metals
• Characteristics of Ferrous Metals with examples
• Advantages/Disadvantages of Ferrous Metals

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METALS

• Metals are Solid at room temperature, except
  mercury, which is liquid !
• Metals have very high melting point.
• Metals are shiny when they cut.
• Metals are good conductors of heat and
  electricity.
• Metals are usually strong malleable so they
  can be hammered into shape.

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METALS

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METALS

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METALS

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METALS

• Ferrous Non-Ferrous Alloys
• Containing iron Do not contain iron.
  A mixture of
• almost all are e.g. aluminium,
  metals, or a
• magnetic. copper, silver, gold,
  metal small
• e.g. mild-steel, lid, tin etc.
  amount of
• cast-iron, tool- other
  substance
• Steel etc.
• Ferrous Alloys Non-Ferrous Alloys
• e.g. e.g. brass (copper zinc)
• stainless steel bronze (copper
  tin )
• steel chromium

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METALS

• METALS ALLOYS
• Metals are available in pure or alloy form.
• Pure Metals such as pure aluminium or pure
  copper, contain only one type of metal. They are
  not mixed with any other metal.
• Alloys are mixture of two or more pure metals.
• Alloys tend to have better strength properties
  than pure metals.
• Alloys and pure metals often have special
  physical properties.

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PROPERTIES OF METALS

• Strength - The ability of a material to stand up
  to forces being applied without it bending,
  breaking, shattering or deforming in any way.
• Elasticity - The ability of a material to absorb
  force and flex in different directions, returning
  to its original position.
• Plasticity - The ability of a material to be
  change in shape permanently.
• Ductility - The ability of a material to change
  shape (deform) usually by stretching along its
  length.

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PROPERTIES OF METALS

• 5. Tensile Strength The ability of a material
  to stretch without breaking or snapping.
• Malleability - The ability of a material to be
  reshaped in all directions without cracking.
• Toughness - A characteristic of a material that
  does not break or shatter when receiving a blow
  or under a sudden shock.
• Conductivity - The ability of a material to
  conduct electricity.

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PROPERTIES OF METALS

• 9. Hardness The ability of a material to
  resist scratching, wear and tear indentation.

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FERROUS-METALS

• Mild Steel
• Composition Iron alloy with 0.3
  carbonProperties Malleable and ductile, and
  therefore bends fairly easilyUses nuts, bolts,
  screws, tubes etc.
• Methods of Identification
• Appearance Bright drawn mild steel has a
  smooth, bright surface black mild steel
  is covered with a blue-grey oxideDropping
  Gives out a ringing noteGrinding Gives off a
  shower of long white sparksEffect of Heating
  Slightly tougher but little change

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FERROUS-METALS

• 2. Tool Steel / cast steel / carbon steel
• Composition Iron alloy with 0.5-1.5
  carbonProperties Tough rather than hard, and
  fairly ductileUses Springs and most tools such
  as hammer heads, drills, chisels, shears
  etc
• Methods of Identification
• Appearance Has a smooth skin of black
  oxideDropping Gives out a high ringing
  noteGrinding Moderate number of red
  sparksEffect of Heating Becomes hard and
  brittle

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FERROUS-METALS

• cast iron
• Composition Iron alloy with 2-4
  carbonProperties Brittle, snaps before it will
  bend. Strong in compressionUses Vices, cylinder
  blocks for car engines, frames for most machines
• Methods of Identification
• Appearance Grey with a granular
  surfaceDropping gives out a dull noteGrinding
  Gives off a few dull sparksEffect of Heating No
  change

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ADVANTAGES OF FERROUS METALS

• High strength to weight ratio
• it minimise the substructures cost, which
  beneficial in poor ground condition. E.g. The
  Newark Dyke Rail Bridge comprises 77 meter
  long, 11.25 meter wide bowstring with 820 tonnes
  of S355 steel.
• This bridge use IMD (Interactive Model
  Technique) reduced the time required to assess
  the dynamic response of the structure.
• This bridge was the first UK steel bridge to be
  designed for the next generation of 225 km/hr
  trains.

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ADVANTAGES OF FERROUS METALS

• 2. High quality material
• readily available worldwide in various
  certificate grades.
• Speed of construction
• Versatility
• steel suits range of construction methods
  sequences.
• Modification repair
• Recycling
• Durability
• 8. Aesthetics
• steel has a broad architectural possibilities.

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DISADVANTAGES OF FERROUS METALS

• Costly waste
• High cost of final finishing polishing
• Environmental issue

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RECAP

• Metal
• Different types of metals ferrous, non-ferrous,
  alloy
• Properties of metals
• Strength
• Elasticity
• Plasticity
• ductility
• tensile strength
• malleability
• toughness
• conductivity
• hardness

• Metal
• Different types of metals ferrous, non-ferrous,
  alloy
• Properties of metals
• Strength
• Elasticity
• Plasticity
• ductility
• tensile strength
• malleability
• toughness
• conductivity
• hardness
• Examples of ferrous metals, uses, methods of
  identification
• Advantages
• Disadvantages
• Homework