Didactic unit # 4 metals part i
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Transcript of Didactic unit # 4 metals part i
TECHNICAL USE MATERIALS (II): METALS
© Federico Fernández Herrera
ENGLISH BILINGUAL 2º E.S.O. TECHNOLOGY
DIDACTIC UNIT # 4
INDEX:
Metal featuresMetals: ferric vs. non ferric
pure vs. alloys Production of metalsWorking with metalsEnvironmental impact
Metal features:
High mechanical resistanceHigh thermic and electric conductivityHigh melting pointHigh densityHigh ductility and malleabilityEasy to recycleSome are magnetic
Cast Iron Steel Cu Al Ti
Traction (Mg/in2) 18 70 18 10 70
Density (kg/dm3) 7,6 7,8 8,8 2,7 4,5
Melting point (ºC) 1.100 1.500 1.080 660 1.800
Metals: ferric vs non ferric
World Metal Production
o Ferric Metals: iron and its alloys. o Non-Ferric Metals: they do not contain iron.
Iron is the most used metal in the world
Metals: o Ferric Pure iron Fe Alloys Fe+C Soft iron
Steel Cast iron
Non-Ferric Pure Copper Cu» Aluminum Al» Titanium TiOther (Sn, Zn, Mg, Ag, Au, etc)
Ferric Metals
Magnetic, abundant, fragile, brittle, easy to get rusty.
Iron (Fe) pure
Iron (Fe) and carbon (C) alloys: Soft iron <0,1 % CSteel (0,1 - 2) % CCast iron (2 – 5) % C
Steel ( 0,1%<C<2% )It´s the most used ferric alloy due to its good features.Ductile and malleable.High mechanical resistance.The amount of carbon increases hardness but fragility too.
Steel mixed with other metals increases endurance (vanadium) and becomes stainless (chrome and nickel).
Ferric Metals (II): Ferric Alloys
Cast Iron ( 2%<C<5% )
Hardness, ductility and melting point: less than steel. Fragility: more
It´s used to produce complicated parts by sand casting and to make hard tools like rasps.
Ferric Metals (II): Ferric Alloys (II)
Non-Ferric Metals: Pure Metals Copper Cu
Tin Sn
•Red coloured if OFC, green, black.•High thermal and electric conductivity•Corrosion resistant•High ductility and easy to weld
• Shiny white coloured•Corrosion resistant•Low melting point
Zinc Zn
Aluminium Al
•White coloured•High corrosion resistance
• White shiny coloured• Light• Non toxic• Stainless (anodization)
Non-Ferric Metals (II): Pure Metals (II)
Magnesium Mg
Titanium Ti
•Very light•Expensive•Violent reaction with oxygen
•Very expensive•Like steel but lighter•Biocompatible
Non-Ferric Metals (II): Pure Metals (II)
Gold Au
Lead Pb
•The most malleable and ductile metal•High corrosion resistance•High thermal and electric conductivity•Expensive, solid value.
•Grey colour•Very soft•Low melting point•Ductile and malleable•Very toxic
Non-Ferric Metals (III): Pure Metals (III)
Brass (Cu+Zn)
Bronze (Cu+Sn)
•Yellow, dark red coloured•Very ductile and malleable•Good tensile endurance
•Yellow, dark green coloured•More endurance than brass•Very corrosion resistant•Musical features•Good for casting and molding
Non-Ferric Metals (IV): Alloys
Aluminum, Copper & Magnesium
Magnesium & Aluminum
Titanium & Aluminum
•Lightness and more endurance than pure aluminum.
•This alloy is more resistant than each metal.
• Cheaper than pure titanium parts.
Non-Ferric Metals (V): Alloys (II)