Flashcards in C2d Deck (9):
What are alloys and why are they useful?
-mixture of two or more metals
-mixture of metal and a non-metal
-often have properties that are different from the metals they are made of
-new properties may make the alloy more useful than the pure metal
Name some alloys and there properties?
*iron and carbon
*harder and stronger than iron (if carbon not higher than 1%), steel corrodes less quickly
*uses: bridges, ships and cutlery
*copper and zinc
*mixture of copper and zincs properties, harder than either of them
*uses:instruments and doorknobs
*copper and tin
*harder and stronger than tin, more resistant to corrosion than tin or copper
*lead and tin
*indefinite boiling point unlike pure materials, gradually solidifies as cools
*uses:solder things together
*alloy containing mercury
What is nitinol what are its properties?
-nickle and titanium
-smart alloy as it has shape memory
-remembering its original shape and goes back to it even when bent
-uses: nitinol glasses frames
Why do iron and steel corrode easier than aluminium for cars?
-aluminium doesn't corrode when wet
-what happens it, aluminium reacts very quickly with oxygen to form aluminium oxide
-this acts as a protective layer, sticking firmly to the aluminium below and stops any further reaction taking place
-oxide not crumbly and flaky like rust, so no falling off
What is the disadvantage of aluminium over steel for cars?
What are the advantages of aluminium over steel?
-low density so cars will be lighter, giving aluminium cars better fuel economy which saves fuel resources
-corrodes less, so longer lifetime
Why is recycling cars important?
-saving natural resources, save money and reduce landfill
What materials do you need to build a car and why?
-steel: strong and can be hammered into sheets and welded together (good for bodywork)
-aluminium: strong and low density (parts of engine)
-glass: transparent (windows and windscreens)
-plastic: light and hard-wearing (internal covering for doors) electric insulators (covering electric wires)
-fibres (natural and synthetic): hard-wearing (cover seats and floors