Metals Flashcards
Stock forms
Sheet - large flat sections approx 1-3mm in thickness
Plate - thicker and narrower than sheet >3mm in thickness
Bar - solid tube form, flat bar ➖, square bar ▫️, round bar ⏺and hexagonal bar
Tube form - hollow in cross section, can be: square 🔳, round ⭕️, rectangular and hexagonal
Structural angular - e.g. H beams/I beams, L beams, T bar and channel
Metal ores
Metals are extracted from their ores e.g. Through crushing, smelting, electrolysis and heating
Ores account for approx 25% of the earths crust
Bauxite is the most common ore
Copper - Chalcopyrite
Aluminium - Bauxite
Tin - Cassiterite
Zinc - Zinc blende
Aluminium properties
Lightweight Ductile Malleable Corrosion resistant Electrical + thermal conductor Can be MIG and TIG welded Melting temperature 660 degrees C
Copper properties
Ductile Malleable Tough Corrosion resistant Good electrical + thermal conductor Can be soldered + brazed Melting temperature 1083 degrees
Zinc properties
Low melting point
Ductile
Very good corrosion resistance
Melting temperature 420 degrees C
Silver properties
Malleable Ductile Corrosion resistant Can be soldered Melting temperature 962 degrees C
Gold properties
Malleable Ductile Corrosion resistant Can be soldered Good conductor Melting temperature 1063 degrees C
Titanium properties
Hard
Similar strength to steels but lighter
Non-toxic and biologically compatible with human tissue
High corrosion resistance, resistance to acids and alkalis and chemical resistance
Poor conductor
Melting temperature -1668 degrees C
Tin properties
Ductile
Malleable
Low melting point - 232 degrees C
Corrosion resistant
Low carbon steel properties
Ductile High tensile strength Tough Malleable Poor resistance to corrosion 0.15-0.3% carbon Melting temperature 1427 degrees C
Medium carbon steel properties
Harder than low carbon steel but less ductile, malleable and tough
0.3-0.7% carbon
Melting temperature - 1425-1540 degrees C
Cast iron properties
Hard outer skin but softer core
Can be cast - good fusibility and can be poured easily
Good under compression
3.5% carbon
Melting temperature 1149 degrees C
Stainless steel properties
Tough
Hard
Corrosion resistant
18% chrome, 8% nickel
Melting temperature 1510 degrees C
High speed steel (HSS) properties
Hard
Tough
High resistance to frictional heat
18% tungsten, 4% chromium, 1% vanadium, 0.5-0.8% carbon
Die steel
Hard
Tough
Durable
Uses:
Blanking punches and dies
Extruder dies
Fine press tools
Bronze properties
Tough
Corrosion resistant
Can be cast
Low friction for metal on metal - e.g. for bearings
90% copper, 10% tin
Melting temperature 850-1000 degrees C
Brass properties
Corrosion resistant
Good electrical and thermal conductor
Melting point 930 degrees C
65% copper, 35% zinc
Duralumin
Equivalent strength to mild steel but lighter
Ductile and malleable
Corrosion resistant
Becomes harder as it’s worked
Aluminium with 4% copper, 1% magnesium and manganese
Uses:
Aircraft parts ✈️
Vehicle parts🚗
Pewter properties
Malleable
Relatively soft
Low melting point 170-230 degrees C
85-99% tin, rest is copper and antimony
Aluminium uses
Drinks cans Aircraft bodies Bike frames Window frames Saucepans Cooking utensils Packaging Baking foil
Copper uses
Electrical wire
Printed electrical circuits
Water pipes
Hot water tanks
Central heating pipes
Zinc uses
Galvanising steel -
Dustbins
Buckets
Farm gates
School fences
Silver uses
Jewellery
Cutlery
Plating other materials
Gold uses
Jewellery
Electronic components
Connectors
Switch components
