Design, Materials And Manufactoring Flashcards
What are the 4 safety signs and an example of each one?
Hazard signs - toxic
Prohibition signs - do not run
Mandatory signs - wear eye protection
Safe condition signs - first aid
What does tensile strength mean?
The resistance if a material
What does compressive strength mean?
The resistance of a material to breaking under compression
What does bending strength mean?
The ability of a material to resist deformation under load
What does shear strength mean?
The ability of a material to resist forces that cause the materials internal structure to slide against ittself
What does torsional strength mean?
The ability to withstand a twisting load
What does plasticity mean?
The quality of being shaped
What does malleability mean?
The ability of being forged
What does ductility mean?
To be able to be deformed without fracture
What is the difference between thermo setting plastics and thermoplastics?
Thermoplastics can be softened when heated where as thermo setting plastics can not
What are some thermo setting plastics and their properties?
Melamine formaldehyde - smooth surfaces
Polyester resin - tough
Urea formaldehyde - colourless
Epoxy resin - good heat resistance
What are some thermoplastics and their properties?
Acrylic - hardwearing PVC - strong ABS - lightweight Nylon - good wear resistance Rigid polystyrene- light but strong
What are some hardwoods and their properties?
Mahogany - expensive and imported
Beech - close-grained
Ash - creamy white or light brown
What are some softwoods and their properties?
Pine - cheap
Cedar - comes from North America
What are some manufactured boards and their properties?
Plywood - made from layers of wood
MDF - made from small particles of wood chips
Chipboard - made of chips from wood
What are some ferrous metals and their properties?
Mild steel - rusts easily
Carbon steel - hard
Stainless steel - soft and light
What are some non ferrous metals and their properties?
Aluminium - soft
Copper - tough
Brass - heavy
What is the difference between ferrous metals and non ferrous metals?
Ferrous metals contain iron where as non ferrous metals do not
What is an alloy?
The combination of 2 metals
What is graphene and some of its properties?
Graphene is a super thin layer of graphite
- thinnest material in the world
- strongest material in the world
- most conductive materials in the world
What is a thermochromic pigment?
Liquid crystals that change colour when the temperature changes
What are some finishing techniques for metal?
Paint, polishing, dip coating, galvanising
What are some finishing techniques for wood?
Paint, varnishing, staining, oil
What are the finishing techniques for plastics?
Polishing
What are the 4 stages to using a line bender?
Stage 1 : mark where you want to bend
Stage 2 : place the plastic on the rests
Stage 3 : turn the strip heater on and flip the plastic over every 30 seconds
Stare 4 : when the plastic becomes flexible, it is placed in a jig
What are the 9 stages to vacuum forming?
Stage 1 : make a former out of soft wood
Stage 2 : place the former in the vacuum former
Stage 3 : clamp a sheet of plastic above the mould
Stage 4 : turn the heater on
Stage 5 : after a few minutes the plastic will be ready for forming
Stage 6 : turn off the heat and lift the mould using the lever
Stage 7 : the vacuum is turned on to pump out the air beneath the plastic
Stage 8 : remove the plastic sheet
Stage 9 : trim excess plastic
What are the 3 stages of soldering?
Stage 1 : make sure that the tip of the iron is in tact
Stage 2 : remove any film from the tracks using a PCB eraser
Stage 3 : clamp in the PCB
What are the 3 stages for pop riveting?
Stage 1 : the 2 pieces of plastic are driller to a size slightly larger than the rivet
Stage 2 : pass through the pop rivet
Stage 3 : pull handles together
What are the 6 stages to brazing?
Stage 1 : clean the steel
Stage 2 : turn compressor on
Stage 3 : turn gas air control on
Stage 4 : raise both pieces of steel using a fire brick
Stage 5 : move flame forward
Stage 6 : a barking rod is then pushed gently against the joint
