Topic 4 - Materials Flashcards
Mass
Physical Property: Relates to the amount of matter that is contained with a specific material (constant), measured in Kg.
Weight
Physical Property: Relies on mass and gravitational forces to provide measurable value, measured in Newtons (force)
Volume
Physical Property: The quantity of three-dimensional space enclosed by a boundary (solid, liquid, gas)
Density
Physical Property: The mass per unit volume of a material.
Electrical resistivity
Physical Property: The measure of a material’s ability to conduct electricity. High resistivity = will not conduct electricity well. Low resistivity = will conduct electricity well.
Electrical Insulator
Physical Property: Reduces transmission of electric charge.
Thermal Conductivity
Physical Property: A measure of how fast heat is conducted through a slab of material with a given temperature
Thermal Expansion
Physical Property: A measure of the degree of increase in dimensions when an object is heated (length, area, volume)
Hardness
Physical Property: The resistance a material offers to penetration or scratching.
Tensile Strength
Mechanical Property: The ability of a material to withstand pulling (apart) forces.
Compressive Strength
Mechanical Property: The ability of a material to withstand being pushed or squashed.
Stiffness
Mechanical Property: The resistance of an elastic body to deflection by an applied force.
Toughness
Mechanical Property: The ability of a material to resist the propagation of cracks.
Brittleness
Mechanical Property: Breaks into numerous sharp shards.
Ductility
Mechanical Property: The ability of a material to be drawn or extruded into a wire
Stress
Tensile force applied to a given area
Strain
percentage of a change in length when force is applied to an initial length
Young’s modulus
Stress/Strain Graph
Elasticity
Mechanical Property: Ability to bend and return to its original shape
Plasticity
Mechanical Property: Ability of a material to be formed into a new shape. When deformed beyond its yield point it does not return to its original shape
Yield Point
Material cannot change back to its original shape.
Ultimate Tensile Strength (UTS)
Material can mantain a maximum load; after this, material moves to the failure point
Failure Point
material breaks
Form & Shape
Aesthetic property: influences interaction/engagement of material (organic or geometric), material influences form of product
Texture
Aesthetic Property: the feel of a material can provide improved grip + psychological ease
Appearance
Aesthetic property: colour/pattern of material, psychological & cultural meaning
Smell
Aesthetic property: powerful connections to memory
Sound
Aesthetic property: sound of material when touched/manipulated - influences user experience
Piezoelectricity
ability to release an electric charge when deformed/with force
Shape memory
Have pseudo-elastic properties that allow their body to return to its original shape after deforming
Photocromacy
ability to change colour when exposed to light
Magnetorheostatic
Changes in viscosity with magnetic forces are applied
Electrorehostatic
Changes in viscosity when electrical forces are applied
Thermoelectricity
Electricity produced directly by heat - joining two dissimilar conductors that when heated produce current
Small Grain Size
Formed through fast cooling: low tensile strength, low toughness, low ductility, high brittleness.
Large Grain Size
Formed through slow cooling: high tensile strength, high toughness, high ductility, high malleability
Alloying
a mixture of one metal with another metal/non-metal. Increases hardness and strength, reduces malleability and ductility (High Speed Steel, bronze,brass)
Work Hardening
The process of increasing the hardness of a metal is done by applying force while the metal is cold. (plastic deformation) - usually for smaller grain sizes
Tempering
Applying heat after work hardening reduces hardness and stiffness and increases toughness and ductility.
Super Alloys
High degrees of mechanical strength, resistance to corrosion, creep, oxidation and surface stability.
Creep
Slow expansion/deformation of a material overtime
Oxidation
the reaction of a metal with oxygen (rust)
Sustainability of Super Alloys
easily and indefinitely recyclable, reduces the energy required to produce new metals, produces less waste
Ferrous metals
Contain Iron: Mild steel, stainless steel, cast iron
Non-Ferrous metals
don’t contain Iron: Aluminium, copper, silver, Tin, Zinc
Soft Wood
Low density, open grain, more flexible, less strong in tension + compression, fast-growing (25-50yrs), renewable resource, low-cost
Hard Wood
High density, high hardness, strong in tension + compression, slow growing (100 yrs), non-renewable
Plywood
strong in compression, Thin (3mm-6mm) = some elasticity, Thick(15mm-18mm) = strong in tension, medium-high density
MDF
Heavy and strong, made of small wood fibres and binder (glue): High density, does not have voids, knots or splinters.
FiberBoard
not strong in compression or tension, lightweight, made from waste wood scraps + glues to bind particles (cheapest engineered wood)
OSB (Oriented Strand Board)
Strong compared to most engineered woods, heavy, somewhat flexible, made out of wood scraps + toxic glue to bind particles.
Seasoning
Kiln + air drying = Process of drying wood so that it can have useful mechanical/physical properties (1-5 yrs).
Treatment of Timber
Protection from insects and fungus by applying chemicals, protection from weather, prevent rotting, improving chemical resistance
Finishing Timber
stains color(provide some UV protection), Pils & Waxes (smooth and shiny, protection from abrasions)
Sustainable Forest Management
Ensuring that cut trees are replaced, preserving habitats and the ecosystem. Aims to provide a balance of social, environmental and economic benefits (future gen)
Glass
Made by rapidly cooling a mix of silica, soda and lima (melted at very high temp), recycled easily, requires a large amount of energy to manufacture, and made out of non-renewable resources
Colours in Glass
modified by adding metallic oxides
Characteristics of Glass
High compressive strength but low tensile strength, low impact strength (shatters easily), can be transparent or opaque, resists stretching to a great degree
Annealed Glass
Breaks easily, long sharp splinters (shards)
Tempered Glass
Heated to a very high temperature and then blasted with cold air: High levels of impact, shatters into little pieces of splinters (shards)
Laminated Glass
Two layers of glass with a sheet of plastic vinyl in between: Cracks under pressure but remains integral
Borosilicate Glass
Resistant to thermal shock, expands less when heated, resists shattering, easily recycled, increases energy in the production process
Fiber Glass
Long strands of Glass woven into fabric form: some flexibility, low electrical conductivity, lightweight, very difficult to recycle
Cullet
Crushed recycled glass is added to the moulted mix. 25% cullet reduces 5% energy production
Thermo Plastics
Linear chain molecules with weak secondary bonds between chains, can be heated and reformed, low production costs
Polypropylene
Thermoplastic: Easily formed, low cost (Shopping bags, straws)
High Density Polyethylene
Thermoplastic: Rigid, low cost (shampoo bottles, resistant to chemicals)
Low-Density Polyethylene
Thermoplastic: Flexible, very cheap (plastic wrap, squeeze bottles)
High Impact Polystyrene (HIPS)
Thermoplastic: easy to machine/shape, vacuum forming, low cost (packaging)
Acrylonitrile Butadiene Styrene (ABS)
Thermoplastic: dimensional stability, high stiffness + strength, high impact, heat resistant, low cost, food safe (children’s toys, cases/devices)
Polyethylene Terephthalate (PET)
Thermoplastic: Lightweight, shatter-resistant, very low-cost (beverage bottles)
Thermosetting Plastics
Linear chain molecules with strong primary bonds adjacent to the polymer chains, once formed, cannot be reshaped with heat, high stiffness and strength, heat resistant
Urea-formaldehyde
Thermosetting plastic: High tensile strength, hard/durable, cannot be recycled (plug/switch covers, high-heat contexts)
Polyurethane (PU)
Thermosetting plastic: Abrasion resistance, non-conductive, cannot be recycled (atuomobile interior)
Melamine Resin
Thermosetting plastic: Highly durable, lightweight, high electrical conductivity, Food safe, kitchenware (cannot be recycled)
Epoxy Resin
Thermosetting plastic: Tough, High compressive + tension strength, resistant to chemicals, toxic, cannot be recycled (adhesive)
Designing for disassembly
labelling of plastic parts with type of plastic to ensure proper recycling
Lightweighting
reducing the amount of material required in a product + packaging
Promoting and using recycled plastics
encourages user acceptance of unique aesthetic properties
Fibers
Raw Form
Yarn
Long, continuous fiber
Threads
thin yarns used in sewing
Fabric
Produced by weaving, knitting or felting
Natural Fibres
High absorbency: low tensile strength, low elasticity, burns but not melts
Synthetic Fibres
Low absorbency: high tensile strength, high elasticity, burns and melts
Wool
Originates from sheep, highly insulative, high durability (socks, suits)
Cotton
Cotton plant (clothing, bedding, furniture corners)
Silk
Made from silk cocoon, the strongest natural fibre, lightweight, thermal properties, high cost, strength (medical stitches)
Nylon
Made from petrochemicals, abrasion resistance, high elasticity (tents)
Polyester
Made from petrochemicals, strong, quick drying, resistant to stretching (seatbelts, fishing nets)
Lycra
Made from petrochemicals, very high elasticity (sportswear, underwear)
Weaving
interlocking yarns at a right angle to create fabric
Knitting
manipulating yarn in multiple yarns to create a tube
Lacemaking
Weaving of yarns and threads into delicate, open patterns
Felting
Compressing and matting fibres together
Carbon Fiber
lightweight, high compressive strength + stiffness + hardness (Cars and space craft)
Sheet (Composites)
materials laminated or layered to create a composite material
Particles (composites)
can be added to composite mixture: increases hardness and durability
Matrix
“glue” that binds particles and fibres together, hardens through a chemical reaction
Pultrusion
Composite material is pulled through a former
Lamination
Laying down sheets with a matrix in between them
Economies of scale
increased cost savings associated with higher production runs
One-off production
Only one item produced: requires specialized tools(skills, higher cost
Batch Production
Limited volume of items manufactured - integrated process, specialised machines, process and workers
Mass production
large scale production, needed in very large quantities + requires little design (economies of scale)
Continuous flow
Large-scale production of goods, highly automated process
Mass customization
allows customers to select aspects of design, uses Computed aided Manufacture (CAM), benefits from economies of scale
Design for Manufacture
designing for optimum use of existing manufacturing capability
Paper-based-Prototyping
Additive Manufacturing Tech: layers of paper glued together to create a 3D shape, cost effective
Laminated object Manufacturing (LOM)
Additive Manufacturing Tech: Creates a 3D product by cutting polymers into thin slices and joining/glueing the slices together
Stereolithography (SLA)
Additive Manufacturing Tech: liquid, photosensitive resin is poured into a tank, hardens/polymerizes with laser
Fused Deposition Manufacturing (FDM)
Additive Manufacturing Tech: Laying down thin layers of material (usually plastic) extruded through a nozzle
Turning
Subtractive Manufacturing Tech: Rotating a material along a horizontal axis while a cutting tool is moved along the surface to remove material
Milling
Subtractive Manufacturing Tech: Rotating a bit over the surface of a material, moving on a vertical axis
Drilling
Subtractive Manufacturing Tech: Spinning bit moving up and down the z-axis to create a hole in a material
Abrading
Subtractive Manufacturing Tech: Using an abrasive to grind/rub away excess material (grinder, sander, polishing)
Adhesive
Permanent joining technique, chemical substances that create a bond between surfaces when dry
Welding
Permanent joining technique that uses high heat to join two similar metals, strong bond, great skill needed
Brazing
Permanent joining technique that uses lower heat and filler metal to join two parts - joining different metals together
Permanent Fasteners
Nails or rivets that bind 2+ pieces together
Temporary Fasteners
Nuts and Bolts, screws, Velcro, knock-down fittings, cable to tie
Injection Moulding
Injecting a liquid material into a mould. As the material is heated and then cooled, it takes on the form of a mould.
Blow Moulding
Inflating a hot hollow plastic inside a mould. The heated material takes the form of a mould
Compression Moulding
A heated sheet of thermoset plastic is placed into a mould. The mould then applies pressure to shape the plastic.
Rotational Moulding
A heated hollow mould is rotated as thermoplastic is poured in. The liquid plastic takes the form of mould as it moves around the interior.
Thermoforming
Heating of a sheet of thermoplastic to the point that it becomes pliable and soft. It is then placed into a mould to be formed into a shape. (vacuum forming)
Laminating
Laying down of thin layers of material joined with an adhesive.
Casting
Pouring molten metal into a mould
Craft production
Small-scale production focused on manual skills, custom-designed, highly skilled/specialised products, low economy of scale, time-consuming
Mechanised production
Volume production involving machines controlled by humans, increases speed, productivity, quality, high cost, increased pollution
Automated Production
Volume production involving CAD, CAM, and CNC: higher quality, increased productivity (24/7), lower labour costs, and economies of scale.
Assembly Line
Products/components are moved continuously along a conveyor: economy of scale, high production volume, limited customization, and expensive.
Computed Numerical Control (CNC)
Computer control of machine for manufacturing complex parts: highly accurate, efficient, customisable, optimised materials, high-cost
1st generation robots
Simple robots that do one task cannot respond to changes in environments (don’t have any sensors)
2nd generation robots
Use sensors to respond to the environment (light, distance, temperature, pressure, radar) and complex codes so that it can operate autonomously - multitask
3rd generation robots
Use of artificial intelligence to accomplish tasks. Can learn and operate without human supervision
Robot Teams
Production lines make use of robot teams to perform complex tasks, increasing efficiency
Machine to Machine
networking of robots together: sharing info + instructions