Metals Flashcards
What is a ferrous metal? What are some basic properties of them?
They are iron based metals which are magnetic and rust.
What happens as you increase the carbon content of iron?
The higher the carbon content the more brittle and hard it becomes.
Give some positives (4) and some negatives (1) of Mild Steel and examples of it in use (2). What is it’s carbon content?
\+ Relatively cheap \+ Ductile \+ Soft \+ Tough - Rusts Car bodies and white goods (fridges etc) Carbon steel content: 0.25%
Give some positives (3) of Medium Carbon Steel and examples of it in use (1). What is it’s carbon content?
\+ Quite ductile \+ A little hard \+ Can be tempered Springs Carbon steel content: 0.5%
Give some positives (3) of High Carbon Steel and examples of it in use (1). What is it’s carbon content?
\+ Quite hard \+ A little ductile \+ Can be tempered Carpentry tools Carbon steel content: 1.5%
Give some positives (2) and some negatives (1) of Cast Iron and examples of it in use (3). What is it’s carbon content?
\+ Not ductile \+ Hard - Brittle Vices, clamps and engines Carbon steel content: 3.5%
What is a non-ferrous metal? What are some basic properties of them?
A metal that contains no iron. They are non-magnetic and do not rust.
Give some positives (6) and some negatives (1) of Aluminium and examples of it in use (2). What ore does it come from?
\+ Malleable \+ Ductile \+ Very conductive of heat and electricity \+ Light \+ Self protects \+ 100% recyclable - Expensive, due to electrolysis Aircraft and castings (with silicon) Comes form bauxite
Give some positives (5) of Copper and examples of it in use (1).
\+ Non-toxic \+ Malleable \+ Ductile \+ Very conductive of heat and electricity \+ Connected together easily Plumbing
Give some positives (3) and some negatives (1) of Gold, Silver and Platinum and examples of it in use (2).
\+ Excellent electrical conductor (Gold) \+ Non-corrosive \+ Hypo-allergenic - Expensive Jewellery and sim cards (Gold)
Give some positives (2) of Zinc examples of it in use (1).
+ Low melting point
+ Non corrosive
Plates ferrous metals
What is an Alloy?
An alloy is a mixture of two or more metals to get the best proprieties of the base metals.
Give some positives (3) and some negatives (1) of Dualumin and examples of it in use (1). Is it ferrous or non ferrous and what is it made from?
\+ Very high strength \+ Very light (lighter than aluminium) - Very expensive Used in structural components of aircraft It is a non ferrous alloy 4% copper and 95% aluminium
Give some positives (3) of Bronze and examples of it in use (3). Is it ferrous or non ferrous and what is it made from?
\+ Easy to work \+ Easy to cast \+ Self lubricating Sculpture, coins and bearings It is a non ferrous alloy Copper and zinc
Give some positives (3) of Stainless Steel and examples of it in use (3). Is it ferrous or non ferrous and what is it made from?
\+ Tough \+ Wear resistant \+ Corrosion resistant Sinks, Cutlery and Prison toilets It is a ferrous alloy Steel 80% Chrome and nickel 20%
Give some positives (3) of High Speed Steel and examples of it in use (1). Is it ferrous or non ferrous and what is it made from?
\+ Very hard \+ Can be sharpened to a very sharp edge \+ Will cut when hot Cutting tools It is a ferrous alloy Steel, Tungsten, Molybdenum, Chromium, Cobalt, Aluminium
Describe extrusion.
Metal is put in a hopper which places it into a tube which pushes them into an archimedean screw. This then takes them though a heater which makes it molten. The metal is extruded though a simple dye and then cooled. This is an infinite process which is cut to length.
Describe blanking.
Sheet metal is placed onto the machine. A punch then comes down on the metal and pushes its shape out of the metal though the die, to form a blank.
Describe press forming.
Sheet metal is clamped over a female mould a former then comes down onto it forming the shape of the female mould. This is only good for relatively shallow shapes like car bodies.
Describe cupping.
When a punch pushes a metal sheet into a die to make a cylindrical cup like shape.
Describe deep drawing.
An object made by cupping is placed on a slightly smaller dye so when the punch pushes it down the metal is made thinner.
Describe embossing.
Sheet metal is clamped over a female mould a former then comes down onto it forming the shape of the female mould. Similar to press forming but is more intricate and shallow, makes quality street lettering on tines.
Describe spinning.
A metal sheet is clamped onto a lathe like machine, next to the mandrel. whilst spinning the sheet is pushed onto the mandrel to make the shape. You can tell if an object is formed like this if it has radial marks. Makes deep and tapered shapes.
Describe casting sand.
Used for ferrous metals. Green sand is placed in a cope and drag (two parts of the mould) a model of the object is made placed in the sand to make a mould cavity (has a runner and riser to pour metal in which are cut of after cooled). The metal is then poured into the runner to fill the cavity. This cools and the object is formed. The objects have a sandy texture and the mold has to be re made each time.
Describe die moulding.
Used for non ferrous metals. A plunger pushes molten metal from a chamber though a nozzle into the cavity in a die. This then cools and the die is taken apart, the object is ejected by ejector pins. Very much like injection molding.
