Metals

Metals

Types Of Metals

the range of metals are classifeid as Non Ferrous and Ferrous

Metals can then be seperated under these headings into Alloys and Non Alloys

Ferrous Metals: Metals that contain iron and carbon

Non Ferrous: Metals that do not contain Iron

Ferrous Alloys: Mixture of two metals, atleast one of the metals contains iron and carbon

Non Ferrous Alloys: Mixture of two metals that do not contain carbon or iron

Ferrous: Mild Stell; Strong and cheap, can rust ( car bodies and white gold)

High Carbon Steel; Harder than mild steel, hard to work and can rust (drills and files)

Cast Iron; Hard, Brittle under impact ( brake discs, engines)

Non Ferrous: Aluminium; Leightweight, cheap, rusts easily ( car bodies, screws, nuts)

Brass; Strong, ductile, looks good ( door furniture, door nobs, electric parts)

Copper; Soft metal, good conductor of electricity ( wires, pipping)

Ferrous Alloys:Stainless Steel
High Speed Steel
Die (tools) Steel

Non Ferrous Alloys:Brass
Bronze
Duralumim

Gold is the only metal that is extracted and usable without processing, all other metals are from ores

Common Metal Ores:
Iron
Copper
Aluminium
Lead
Tin
Zinc

25% of the earth crust is made up of metal ores, Aluminium is the most common followed by iron

The rarer the metal the more expensive

Timbers

Polyurethenevarnish cab ve sprayed onto wood rather than coated on with a brush, can get gloss or matt finish

Wood stain can be used to protect the wood aswell as staining it another colour

Oils can be rubed into the wood, no gloss affect, inhances the colour of the wood

Preservatives - tanalised timber, no varnish needed as ot has been injected, used for sheds, decking, injecting the wood inhances its like by 4x as long, is seasoned in a kilm and takes the moisture out of the wood, exterior wood not interior

Paint - must put a primer on it before used, primer seals the timber from moisture and lets the paint stick to it.

Man Made Board

Uses waste material, has no moisture in it not allowing the board to bend

MDF - medium density fibreboard, Cheap, fine wood chippings in glue and compressed together to forum a sheet, no structure, will blunten saw due to the glue being harder than the wood

Plywood - most used for furniture because its veneered (product underneath with a coating on top to make it look aesthetically pleasing) there are two types of vaneer : sliced and rotory
, the grain on each sheet goes opposite to make the plywood have a stronger structure and stop it bending

Chipboard - wood chips glued together, blunts the saw like MDF, can be as thick as you like, very strong

Hardboard - cheap, very weak, fibreous, absorbs water, used for backing on some furniture like cupboards

Blockboard - Vaneered on the top, wood stuck together in the middle in several sections

Flexy ply - machined with grouves in allowing it to bend in a certain direction

Aeroply - Used for outer skin of aircraft, very expensive, has a stright grain, the wood used to form it is Beach

Maplex - new MDF, high grade MDF, High Desity

Man made board has no iragularites such as Knots

thickness of board goes in multiples of 3mm (3,6,9,12,15,18,21,24) and a height of 1120 mm

Structure Of Wood

wood is a fibreous material

fibres run along the trunk

55% of tree is cellulose, 28% lignin resin, this holds the tree together

What happens to timber before its the product

harvest - cut the tree down

conversion - cut the trunk into boards

seasoning - reducing the moisture content, can be dryed naterialy or in a kilm

Natural Timbers

Lumer has been failed, still in its log shape

Wood is the material

Timber is the processed material

Hardwoods - Diciduous trees, loose there leaves in the winter
(Ash, oak, beech, teak, walnut)
Slow growing

Softwoods come from coniferous trees, trees with needles and cones, evergreens
(larch, spruce, scots pine, douglas fur)
Fast growing

Indiginous - point of origin (oaks from england)

Softwoods are cheaper to buy due to it being able to grow quicker, it is a more sustainable source than hardwoods.

The age of a tree can be found out by counting the amount of anual rings

the dark rings show the winter months, light rings show the summer, thickness determins how long the summer or winter was. In the winter the lines are dark due to the resin protecting the tree from the cold and in the summer less resin as it isnt as cold.

FSC symbol is placed on wood to show it is from a sustainable source, for every tree they cut down they replace it with two.

I Should Never Of Purchased

I should of never purchased

I should of never purchased my phone “Sony ericsson C902”, the phone is aesthetically pleasing, with many functions and uses and when its working is the best phone i have owned and used. The issue with the phone is there’s too much technology for it to handle and often has a fault that can only be sorted by switching it off.

· The socket on the phone becomes loose, not allowing you to charge your phone or listen to music through the headphones.
· The memory card gets scratch easily breaking it, the small needle like pins in the memory card holder scratch it making it unable to use.
· The touch screen on the camera and video option fades making it hard to take photos and videos.
· The key pads numbers and letters fade making it hard to use the phone and text.
· Camera screen and lens gets scratch making photo and video quality decrease.
· The key pad is very compact and hard to use when texting as you can press keys you don’t intend to use.
· Often freezes and needs be restarted due to, to much memory being used.
· It was over 200 pounds to buy and within 6 months I have to replace it.
· The design features brake such as the logo and name on the back come unstuck.