Processing techniques Flashcards
What is the primary objective of processing techniques on materials?
To understand how processing techniques affect material properties.
What are the two main factors that can be altered through material processing?
- Grain structure
- Composition
What is the characteristic feature of all metal forming processes?
The reshaping of raw metal stock into a finished part.
What is plastic deformation?
The change in physical shape of a material by applying force greater than its yield strength.
How is bending achieved in metal forming?
By using a brake press or similar type of press machine.
What does rolling in metalworking accomplish?
Reduces the thickness of metal and makes the thickness uniform.
What is hot rolling?
A process where metal is rolled above its recrystallisation temperature.
What property changes occur in steel during hot rolling?
Enhanced toughness and ductility.
What is roll forming?
A process that shapes metal as it passes through successive sets of rollers.
What distinguishes hot working from cold working?
Hot working is performed above the recrystallisation temperature, while cold working is performed below it.
What is the result of hot working on internal stresses?
No internal or residual stresses build up.
What is cold working also known as?
Work hardening.
How does cold working strengthen metal?
By plastic deformation at temperatures below the recrystallisation temperature.
What happens to cracks during hot working?
Cracks and pores can be removed.
What is stretching in metal processing?
A process that stretches and bends a workpiece simultaneously over a die.
What is deep drawing?
A method where a metal sheet is clamped over a cavity-shaped die to form hollow components.
What is sintering?
A process of forming a solid mass of material through heat and pressure without melting.
What properties can be enhanced through sintering?
- Thermal conductivity
- Electrical conductivity
- Material strength
- Translucency
What is the difference between thermoset and thermoplastic powder coatings?
- Thermosets form chemical bonds and are not recyclable
- Thermoplastics become liquid upon heating and are reusable
What are the three groups of casting materials based on mould design?
- Expendable mould
- Permanent mould
- Composite mould
What is sand casting?
The most common type of expendable mould casting using sand to create the mould.
What is the process of injection moulding?
Melting plastic pellets and injecting them into a mould cavity to produce a final product.
What is PMMA commonly known as?
Acrylic.
What are the properties of ABS?
- Strength
- Impact resistance
- Corrosion resistance
- Flexibility
