hi guys this is a video covering a wide range of materials that you need to be familiar with for your GCC or a level DT exams I'm luckily materials is a topic that doesn't change too much once you get to a level so the content overlaps between GCC and a level I've listed the material categories here that I'm going to talk about physical versus working properties Woods Composites Metals papers and Boards textiles smart materials and ending with problems two disclaimers before I begin firstly I'm a your 13 student making this video so if there are any mistakes or Corrections I'll list them in the description and the comment section of this video though I've tried my best to fact check everything against textbooks my notes and the internet secondly this video covers many exam boards however not 100% of everything will be applicable to you so have your specification or your revision list handy and check what materials you need to know for your exam okay starting off with the difference between physical properties and working properties so physical properties are the traits a material has before it is even used working properties are how a material behaves when it's manipulated when there's Force um added to it or there's forces on it so some examples include of physical properties density which is basically the mass per volume of a material the weight how heavy something is the moisture content how much water is in the material normally in woods shrinkage when materials um when when normally Woods lose water they shrink sometimes thermal conductivity electrical conductivity so ability to conduct heat or or an electric current the grain so the direction of like wood grain is um a physical property color the Aesthetics the color of material texture transparency in normally papers and Boards um to what extent like can pass through that material chemical resistance and absorbency then we have working properties so stuff like workability which is um how easy it is to cut shape finish or even like carve that material machine ability the ease of being processed using machines um stability so a lot of manufactured boards are quite stable they don't warp or twist easily abrasion resistance flexibility tear resistance crease resistance these are more in um textiles or papers and Boards printability so the ability to accept printed ink or images most papers and Boards have good printability so they can um basically Graphics can be printed on um hardness which is the resistance to scratching or indentation the hardness is um different to toughness um hardness is scratching toughness is like shock um and other forces so different types of strength as well tensile strength compressive strength elasticity the ability of a material to return to its original shape after being deformed and permeability malleability ductility these two ones are really common and then relability and modability so in exams often you'll see questions like explain one working property off or give two physical properties off um really common exam questions and here are a list of your physical properties and working properties okay onto our first actual material so Timbers or wood woods so there's hard woods and soft Woods hard woods come comes from Broad Leaf decidious trees where soft Woods come from coniferous trees like Christmas trees they have needle like leaves and softwoods are cheaper and faster growing because the trees grow faster and then Hardwoods um come from sort of trees that have so bigger leaves okay so there's five Hardwoods which I've mentioned here Oak mokan jell Tong Beach and BSA so these directly Cate with the a level lxl specification and there's four softwoods Redwood large pine Cedar so starting off with oak oak is a hard material which means it does not scratch easily it's resistant to wear and te and it has an attractive grain so this is a piece of oak furniture it contains tanic acid which will corrode steel fix things so often it has to be finished so it does not end up corroding um other metals um it is the strongest and densest hardwood so densest means it has the greatest mass per volume it's used in furniture barrels Etc Hardwoods tend to have a close a closer grain which means they carve better because they're less likely to split or splinter if you can imagine softwoods have more basically holes in them have um more empty space so they're likely to Splinter Etc um then mahogany has a dark red color it's duable stable it's used in musical instruments in cabinets Etc jell tongue um slightly different hardwood it's um got a softer texture soft spongy texture and it's easy to work with hand tools it has a load density and a lower durability compared to the other Hardwoods it's similar to BSA actually we'll talk about a second but has a tighter grain so Bala is a super lightweight um hardwood people often think it's a softwood but it's actually a hardwood it has a straight grain low density light weight it's used in model making so often in in school you maybe you would have seen this material um in like model airplanes model houses for example here is an example of like an architecture model made with Bosa is super soft Norm almost like you can um carve it with your fingers you can snap it you can like squeeze it quite um yeah a low density material um and yeah it's actually a hardwood even though it has sort of softness and it's a lightweight material okay and then Beach is the final hardwood I'm going to talk about um has a straight grain with a fine uniform texture making it easy to work with it's used in mallets it's used in children's toys used in chopping boards Beach is um yeah quite a hard material and it has a sort of slightly lighter color compared to Bren mahogany so an acronym you can use to learn um just the names of these um hardw is b o m BJ BSA Oak Beach mahogany jelly okay now to move on to softwoods so Redwood large pine Ceda are the four you need to know for specifically a for a Lev XL so Redwood looks like this not so quite common it's a lightweight material but has good strength it's used in structural components and eternal decorative moding so for example architraves um large is a hard tough waterproof material but it's prone to splitting so it needs to be pre-drilled it's used in bow building fences Pine is a very common softwood um it has a straight grain it's naughty so quite you can see um quite common property of softwoods is that they're naughty they have knots in them um and pine is susceptible to what so it has to be finished it's lightweight low density and used in sort of basic furniture and stools and so on and used in construction then Cedar is quite interesting softwood um it has this slightly darker richer color to it it's got natural resistance to Decay insect infestation which is why it's used um in outdoor cladding used in fences here you can see outdoor chairs made from Ceda um because it's naturally resistant to Decay and rotting Etc so five Hardwoods four softw um generic properties of Timbers so for example hardness as we said earlier is the resistance to scratching workability how easily it can be cut shaped car strength here you can see five different types of strength tension compression share torsion bending so in bending there's tension on one side compression on the other side okay onto our next material which is going to be Composites so we have some timber timber based Composites and some other of non-o based Composites so starting off with MDF super common material it has a smooth surface it's dimensionally stable so it's not likely to war because it's man-made it's highly Su highly susceptible to moisture damage and it expands when it absorb water so yeah MDF and water does not go well together you have to finish it in some way to make it waterproof to make it resistant to water um it's easily shaped and it takes paint well it has a really sort of nice texture so it absorbs paint really well a misconception is that it's lightweight it's very common in the exam to say oh material is lightweight MDF actually is not lightweight it's really dense it's heavier than a lot of Hardwoods as well and it comes in large sheets which most manufactured boards do um normally comes in um 1.2 M by 2.4 M sheets then in plywood which is similar to MDF it has an odd number of layers so it's made up in this layer form like this um the reason it has an odd number of layers is so the top and bottom grain direction is parallel so three three layers five layers Etc um it's a strong and stable material similar to MDF it has a high strength to weight weight ratio so it's relatively lightweight for how strong it is it's using Furniture Tabet Tre a lot of different things and PID is probably the material you're most familiar with using it in school it's available in various thicknesses so normally in multiples of three so 3 6 9 12 Etc comes in large sheets um and this is what it looks like so if you have to identify it based on a picture this is what ply looks like it has it very visible layers then let's talk about blockboard so blockboard is made from solid wood strips or blocks like this picture shows that are sandwiched in between thin layers of wood veneer um so relatively almost low quality material but really strong um and used in construction then hardboard um it's used in the back of wardrobe backing so if you can imagine like having a freestanding wardrobe the thin material at the back that's just there as a show it just to um yeah to provide the backing um that's normally what hardboard is used in has a smooth surface and it's tough even though well I guess in the um wardrobes it's quite thin material so you wouldn't necessarily say it's tough then chipboard is the S third most popular um or like another manufactured board it's strong in all directions it's really strong it's made almost like MDF but it's made in these um chips larger chips it looks like this it's quite unattractive as such um but the um manufacturing of it makes it really strong it's not attractive at all it's used in flat pack furniture with veneers so a lot of like Ikea furniture is made from chipboard or even particle board which is another type of chipboard comes in large sheets and it's available in various grades so you have chipboard that's made for outdoor use it's construction grade chip chipboard also exists and comes in various densities depending on what um like purpose you're looking for and then so those are um what is that five Timber based Composites then we have two other ones we have um carbon fiber reinforced plastic and glass reinforced plastic which are polymer based Composites so carbon fiber and polyester resin gives you carbon fiber reinforced plastic it's this material here um it's lightweight corrosion resistant tough has a low Thal expansion and it's quite a stiff material it's used in cars it's used in um yeah sports equipment and it's made made using the layup lamination process so that's where you have um sheets or like matting is called of um carbon fiber it's pressed into a mold and then resin is poured on top to fill the spaces and this when the resin cures this combination of having the fibers along with the resin almost like paper mâché is what gives it that hard shell like structure and then glass reinforced plastic similar thing using um glass fiber and polyester resin it's lightweight tough it's an electrical insulator it's transparent to radio waves it's used in boats in boat holes water tanks and just like um carbon fiber reinforced plastic is made using the layup lamination process now to talk about Metals we have um Ferris Metals non- feris metals and Alloys so here we have three Ferris Metals um a ferris metal means has ion in it so this symbol in the per table for ION is Fe that's where the feris comes from um f Mets are magnetic they can rust and they contain iron so mild steel medium carbon steel and cast iron are three types of feros metals basically iron mixed with carbon um so mild steel has has approximately 0.3% carbon in it it's also called Low carbon steel it's ductile has a high tensil strength it's tough It's malleable um but it has a a poor corrosion to resist to sorry a poor resistance to corrosion it's used in bolts car bodies and white goods white goods are sort of appliances um that normally have like a white like a frame around it so this like washing machine for example the body itself would be made from low carbon steel and the white comes from dip coating um so the reason it's dip coated is to protect it from rust because otherwise um the material itself the mild steel would rust um it's also mild steel is also used in um like the polypop chair the legs of your sort of normal school chairs and again those are painted to protect against rust medium carbon steel has approximately 0.7% of carbon in it it's harder than mild steel but it's less ductile um it's malleable and it's tough it's less malleable but it's tougher it's used in gardening tools machine parts a lot of like Gars and bolts and stuff is used in um is what medium carbon steel is used in and then lastly cost iron is what your um bench VI are made of and like manhole covers so it's got hard outer skin however the core itself is really is is good under compression so of course Ace itself is used to create the compressive Force so you have um cost IR good for compression um so with each all three of these as you increase the carbon content the strength and hardness increases but it becomes more brittle so brittle means um it can't resist like really strong quick um impactful Force so if you smash like a vice with like a really strong Hammer um it would probably shatter into like a load of pieces so those are your three feris metals and then we have a pair three um Alloys so alloy is a mixture of two or more types of two or more Metals um to basically normally to enhance properties so brass stainless steel and derum so brass is an alloy of 65% copper and 35% zinc it's corosion resistant it's an electrical and thermal conductor it costs well it's hard malleable and ductile normally as we've seen if a metal is malleable it's also duct tile and then malleable means it can be um almost hammer or shaped um without fracturing and the dark to means it can be pulled or stretched into some like almost like a string or like like a pipe like copper pipes are duct cuz copper is a duct material it can be basically pulled into a wire so here um we have like almost washers or bols or something that are made from Ross stainless steel is tough hard corrosion resistant smooth nonporous um all metals are nonporous it means it doesn't absorb water it's easy to wipe normally made from chrome nickel silicone maganese and used kitchen wear Cutlery a past question has been um explained one property of stainless steel which makes it suitable for cutlery so you can say it is not it is coion resistant which means that it will not rust therefore it will be safe to use with food um to giving a point explanation and then linking it back to the question so cery used with food that's your three marks a three mark question here um so that's St is steel and then um jum is lightweight it's a strong material cal It's Made From aluminium copper and magnesium it's used in aircraft and vehicle pots so those are three Alloys then we have four um these four here four non-fur metals which do not rust are not magnetic and don't contain iron so aluminium copper tin zinc aluminium is lightweight ductile malor um aluminium is the one metal that for sure is lightweight it's used in drink cans AO bodies bike frames so for example here the bike frame made from aluminium copper it's for te resistant malleable ducto again we see malleable and ducto together it's soft it's used in wire electrical wire and water pipes and yeah um because it's also um a therond so it can carry heat basically and then tin is ductile malleable used in soft solder so soldering um like welding it's used in soft yeah soft solder used in circuit boards um it's a coating for food cans um and basically yeah it's used as a productive coating the steel as it does not rust so if you think about like baked beans cans and stuff normally sometimes um covered in tin to stop the stainless steel from rusting and then lastly zinc is has good corrosion resistance used in buckets and a protective coating for other materials so um the big sort of Street pipes or Street lamps um they're often coated in zinc um it's called it the process of galvanizing it has that like almost um that metallic finish to it that's what that's what steel does and is also used in diting um an acronym you may find helpful to remember these four nonfer metals is actz your aluminium copper tin zinc now on to papers and Boards we have four types of paper and six different boards so layout paper um starting from the thinnest is thin translucent so it's used for transposing images used in like architectural drawings um it's used in sketch pads and it's around 50 g per square met GSM so GSM stands for G per square meter it is is used to measure the mass of paper so for example 80 GSM means that 1 square meter of that paper weighs 80 g next up tracing paper is slightly thicker than layout paper it's used for copying images when drawing or um seeing an image underneath so in mats for example youd use tracing paper you would have used tracing paper um at 60 to 90 GSM then copy of paper is inexpensive general purpose it can be colored so this is your standard a for or printer paper it's used for general office printing it's 180 GSM then cartridge paper is the heaviest it's off-white with a slight texture it's used for sketching so this sketch pad for example um has 50 sheets of 140 GSM so that would be cartridge paper it's between 120 to 150 GSM those are your four types of paper going from the lightest to the heaviest um then onto boards we have mounting board it's made from compressed cotton fibers it's used for picture mounting or modeling then corrugated board which is just your normal cardboard it's made from cotton board out outer layers and a corrugated middle layer so this has the two sort of thinner layers of col on the outside and then this fluting is the main thing that gives it it um its strength because although the fluting can be compressed downwards it's strong upwards because of all the ridges it has so this would be um so cardboard is strong in One Direction weak in the other it's used in protective packaging as it's able to um provide protection against impact So like um when you're moving house or the boxes and stuff made from corrugated board then foring box board is made for multiple layers of Pulp um the top layer is pigmented it has good printability and it can be embossed so this picture here shows embossing where there's like a um a difference in layers difference in texture so this process is called embossing and folding box board is used in packaging then F line board um is used in the food and drinks industry um it is a board with foil applied to provide water resistance it's used in drinks packaging and milk Cottons um then solid whiteboard is a high quality card which is smooth on both sides which makes it good for printing um it's used in greeting cards and packaging so for example this here is just a a plain greeting card made from solid by board then phone board um lastly phone board is has um a foam middle cord with two outer layers of card and it's used in presentation boards so um a p exam question has been explained two working properties of solid white board that make it an ideal material from which to make aice short and story that has moving parts so because it's explained two properties is going to be a fourar question and it's working properties not physical properties so solid whiteboard is rigid which means that it will not be easily damaged by repeated use that would give you two marks and then solid whiteboard has a smooth surface which means that it will Glide smoothly with little friction um in this case being the context of a children's toy that has moving Parts continuing with textiles we have natural fibers and man-made fibers so cotton linen and um nylon sorry cotton linen and wool are all natural fibers cotton comes from the cotton plant it has high absorbency so it dyes easily so Dy different colors easily um it's got high breathability so it's good for clothing one next to the skin and there is a static charge um cotton is used for towels bedding clothing so these sorts of towels are usually made from 100% cotton um linen is made from flax fibers it has similar properties to Cotton so it's durable lightweight however it has a crispier texture and it's stiffer than cotton which is why it's used used in suits um and it has a higher wrinkle resistance so lenen is used in suits and elegant clothing because of its crispiness so cotton is too soft for this and it's used in home furnishings um so for example this suit made from linen um with the specifically with textiles it's important to know examples of when it's where the material is used so you can think about properties you can think about cotton being able to absorb water cuz towels are good for absorbing water then wool is made from the fleece of sheep it has high warmth below Je ability um a key property of wool different to the other two natural fibers is that it's inherently flame resistant so it does not catch fire easily and it has self-extinguishing properties so therefore it's a safe choice in environments where um being able to catch on fire or like fire safety is a concern so those three are natural fibers General properties amongst all three of these natural fibers is um they're all um breathable so they have good breathability they are absorbent have high absorbency and are biod aable then we have a couple of um non or manmade um textiles so polypropylene is used in sports wear so for example like football shirts because it's quick drying and lightweight it draws sweat of um from the skin from your skin to the surface of the fabric so then it can evaporate quickly um which is a advantage of this material then nylon is not absorbent it's durable has high elasticity it has high TI resistance and it's breathable it's used as an indust fabric as it's very strong um an exam question in the past has been GI to reasons why nylon may be considered an an unsustainable um fiber because it's made from finite resources um and it will not biodegrade therefore it's not sustainable and then um polyester is incredibly durable and retains shape over time it's crease resistant so it's used in um trousers shorts jackets your um yeah for example like waterproof jackets is made from polyester and then some common texile properties um tenso strength so the three um man-made fibers nylon polyester and polypropylene have high tenso strength elasticity World nylon polyester polyproplene absorbency the three natural fibers and increase resistance the three man-made fibers and then another part that comes up in the a level I think early is textile treatments so proband is a fire retardancy chemical which is used to delay the spread of fire the speed of spreading of fire um PTFE forms thin protective layer on fabric surface preventing stains from penetrating fibers so it for stain resistance and finally water resistance um coing coing the fibers with a chemical to reduce the absorbency and use in outdoor products where for example rain can get absorbed in the textil we have two more material categories left this is smart materials a smart material is when a stimulus which is a change in environment so for example change in heat light electric current causes a change in material properties so thermos Ceramics are a mixture of metallic powder and ceramic powder that's compacted into a mold and formed by heating up the mold and applying pressure so here A change in temperature causes a change in thermal properties which allows for efficient um temperature regulation properties of thermics are they incredibly hard and stable at high temperatures used in automotive parts drw bit tips metal cutting tools um they're called cats so an example is tungsten carbide so here is a Tungsten Carbide drit that can with stand higher temperatures without losing hardness which makes them ideal for drilling through hot Metals as they weren't dull from heat generated so noral high-speed steel drill bids will dull from drilling through Metals um that have a high melting temperature then we can talk about shape memory Alloys which is the probably the most common smart material um here an external stimulus causes the metal alloy to return to its original shape um so for example nitol wire EMB braces which returns to his original shape due to the warm temperature in the mouth so off having um like a straight shape um for example just a straight wire at low temperature then it's deformed at that um low temperature then in the mouth where it's heated it reverts back to its original temperature over time and that's the cycle of um shape mem Alloys then we can talk about thermochromic and photochromic pigments so if something has Thermo in its name it's to do with heat and then photos to do with light so thermochromic pigment a change in temperature causes a change in color simple as that so A use is color changing marks to indicate temperature for children or for vulnerable people um and using thermometers as well then forer to chroming pigment similar to thermochromic pigment a change in light intensity causes a change in color so for example in welding goggles um if the spark from the warden causes a LW of light the um the goggles can immediately switch to a darker color to try and block out that light then um LCDs Liquid Crystal displays and electrical voltage called causes liquid crystals to change from light to dark so here they're used in screens TV screens calculator screens Etc um then Quantum teling Composites qtc's here A change in pressure or strain causes a change in electrical conductivity so used in touch screens um and pressure sensors and then lastly reactive glass a change in external stimulite causes glass to change tint so used in Windows um where for example like big windows in offices and stuff can switch to to like dark tint um to block out to basically stop them from being transparent these are not used in wend goggles because they don't go fully opaque they're just tinted in W and goggles you want the um the lens to go completely opaque lastly and probably most interestingly we have polymers or Plastics so two there's two broad categories of polymers we have thermoplastics and thermosets so thermoplastic is where the polymer can be repeatedly reheated and reshaped so here is the example of um or the diagram of a thum plastic so there's no cross links in between the different um the different lines and then Theros sets the um they can't be reheated and reshaped um once they once they're cured um they can't be reshaped so here they have cross links in between each of the different layers the different strands um which means they're they're locked in they can't be reshaped so a lot of examples of thermoplastics and then a couple thermos sets so first of all um acrylic is a thermoplastic it's tough hard has good chemical resistance it's translucent or sometimes transparent and it's used in car light casings line bending so here example here's an example of line bending um a she of acrylic is heated at those points there and then bent in that shape and also acrylic is used in both tubs um then ABS is used in rigid suitcases because it's tough and it's used in casing so here's an example of a suitcase made from ABS you can clearly see that um abs and a lot of these um Plastics can be pigmented can be colored so that's one advantage it does not need to be painted on top um the metal itself can be pigmented so ABS acrylic um thermoplastics then let's continue with more thermoplastics ldp low density polyethylene I think it's called um has a low level of rigidity it's used in plastic plastic wrapping and disposable shopping bags pet has a high tensor strength and used in detergent or shampoo bottles example this one here polypropylene is used in flimsy ring binders and one unique property of polypropylene is that it has good fatigue resistance so if you can imagine these ring binders here it's all made from one sheet of polypropylene and it's bent and there's two like hinges there that forms the hinges um and it has good fatigue resistance it can be opened and closed many many times without tearing without breaking then PVC is another thermoplastic flexible has good chemical resistance as most of these Plastics do because they're nonporous used inflexible host pipes book protectors so if you have any sort of EX size book or even look books in the library um they have that plastic cover on them normally PVC so that you can tell um you can in the exam you can picture that material and think okay what properties does PVC have um and then PVC is used in food grade vacuum form trays um upvc is opaque has good weathering resistance it's rigid it's used in these pipes window frames doors so this here is upvc um and then okay lastly HTP high density poly is weatherproof translucent transparent used in plastic bottles um it's great for blow molding so the process of blow molding um used to make bottles plastic bottles Etc and then HTP is used in toys and buckets so those I think are all of the um thermoplastics then we have here four Theros sets and then three elastomers or two elastomers so Ura formal deide um is hard heat resistant is a good electrical insulator it's brittle used in domastic um Electric equipment for example plug sockets are here is an example of UA UA forhide used in plug sockets most SL all um thermosets are brittle that's one property across all the different thermosets so polyester resin is rigid um is heat resistant but it's brittle so heat resistance comes from the fact that they can't be um reheated so if there heated it w melt basically which makes a heat resistant but it's still brittle and then it's used in the layout process for glass reinforced plastic and um and carbon fiber rful plastic As I talked about in the composite section and then epoxy resin is rigid clear hard tough used for casting so filling a mold and encapsulation which is how surf boards are made lastly um melamine form up form alide so both of these words have form alide and um resin are those key words for thermosets um so melamine for form alide is a good electrical insulator it's hard it's stable it's commonly used in laminate countertops so the top surface of um some kitchen countertops that aren't made from like granite or like actual um made from Stone the top layer is going to be mam form alide and the inside the middle layer is probably going to be chipboard and then lastly we have two elastomers so an elasta is a material which at room temperature can be deformed under pressure and then returns to its original shape so basically it's elastic so natural robber has high tensal strength low elongation so doesn't stretch that much um has good hard it's an electrical insulator has good cold resistance and this is the rubber used in tires and balloons and then we have neocene which is similar it's tough has good oil and chemical resistance it's abrasion resistant as used in wet suits so those are all the materials in this video hopefully useful for everyone if there's any questions or if there's anything you want to add leave it in the comments good luck for your exams