Presentation on theme: "METALS Learning Objectives: What is METAL?"— Presentation transcript:
1 METALS Learning Objectives: What is METAL? Different Types of Metals – Ferrous, Non-Ferrous, AlloysMain focus of Ferrous MetalsProperties of MetalsCharacteristics of Ferrous Metals with examplesAdvantages/Disadvantages of Ferrous Metals
2 METALSMetals 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.
6 METALS Ferrous Non-Ferrous Alloys Containing iron & Do not contain iron A mixture ofalmost all are e.g. aluminium, metals, or amagnetic copper, silver, gold, metal & smalle.g. mild-steel, lid, tin etc amount ofcast-iron, tool other substanceSteel etc.Ferrous Alloys Non-Ferrous Alloyse.g e.g. brass (copper + zinc)stainless steel bronze (copper + tin )steel + chromium
7 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.
8 PROPERTIES OF METALSStrength - 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.
9 PROPERTIES OF METALS5. 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.
10 PROPERTIES OF METALS9. Hardness – The ability of a material to resist scratching, wear and tear & indentation.
11 FERROUS-METALS Mild Steel Composition: Iron alloy with 0.3% carbon Properties: Malleable and ductile, and therefore bends fairly easily Uses: nuts, bolts, screws, tubes etc.Methods of IdentificationAppearance: Bright drawn mild steel has a smooth, bright surface; black mild steel is covered with a blue-grey oxide Dropping: Gives out a ringing note Grinding: Gives off a shower of long white sparks Effect of Heating: Slightly tougher but little change
12 FERROUS-METALS 2. Tool Steel / cast steel / carbon steel Composition: Iron alloy with 0.5%-1.5% carbon Properties: Tough rather than hard, and fairly ductile Uses: Springs and most tools such as hammer heads, drills, chisels, shears etcMethods of IdentificationAppearance: Has a smooth skin of black oxide Dropping: Gives out a high ringing note Grinding: Moderate number of red sparks Effect of Heating: Becomes hard and brittle
13 FERROUS-METALS cast iron Composition: Iron alloy with 2%-4% carbon Properties: Brittle, snaps before it will bend. Strong in compression Uses: Vices, cylinder blocks for car engines, frames for most machinesMethods of IdentificationAppearance: Grey with a granular surface Dropping: gives out a dull note Grinding: Gives off a few dull sparks Effect of Heating: No change
14 ADVANTAGES OF FERROUS METALS High strength to weight ratioit minimise the substructures cost, which beneficial in poor ground condition. E.g. The Newark Dyke Rail Bridge – comprises 77 meter long, 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.
15 ADVANTAGES OF FERROUS METALS 2. High quality materialreadily available worldwide in various certificate grades.Speed of constructionVersatilitysteel suits range of construction methods & sequences.Modification & repairRecyclingDurability8. Aestheticssteel has a broad architectural possibilities.
16 DISADVANTAGES OF FERROUS METALS Costly wasteHigh cost of final finishing & polishingEnvironmental issue
17 RECAP Metal Different types of metals – ferrous, non-ferrous, alloy Properties of metalsStrengthElasticityPlasticityductilitytensile strengthmalleabilitytoughnessconductivityhardnessExamples of ferrous metals, uses, methods of identificationAdvantagesDisadvantagesHomeworkMetalDifferent types of metals – ferrous, non-ferrous, alloyProperties of metalsStrengthElasticityPlasticityductilitytensile strengthmalleabilitytoughnessconductivityhardness