1.16 Metal Processes Flashcards
Describe the term forming
No material is removed, but materials are deformed to produce required shapes
Describe the term redistribution
The material is changed from one form to another, e.g. liquid metal poured into a mould to take a solid shape
Describe the term wastage
Material is cut away to leave the desired shape
State two features of press froming
Process form: Forming
Shapes sheet metal into 3D forms
Often used in conjunction with robots for lifting the sheet into place
Suitable for mass production or large-scale batch production
State two features of wrought iron forging
Process type: Forming
Uses wrought iron (carbon content less than 0.8%)
Can be hand or hydraulic press process
Suitable for one-off or small-batch production
State two features of cupping and deep drawing
Process form: Forming
Starts with a metal blank
Metal is stretched into shape
Used for large-scale mass or continuous production
State two features of drop forging
Process type: Forming
Use for products that need to be tough and hard
Maintains the internal grain structure which retains the strength
Hot metal billet shaped on an anvil or die and then pressed into shape and cooled
Suitable for mass production
State two features of spinning
Process form: Forming
Product may show parallel lines where the sheet has been forced onto the mandrel
Suitable for mass production or small-batch production
Describe the term addition/fabrication
Process where components and products are made by adding pieces together
State two features of sand casting
Process type: Redistribution
Labour-intensive process
Not a high-quality surface finish
Suitable for one-off or small-batch production
State two features of blending
Process type: Forming
Does not include any punching or trimming of the metal
Simple bending can be carried out in school or college workshops
Used for large-scaled batches in industry
State two features of rolling
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Process type: Forming
Hot rolling metal results in uniform mechanical properties, no deformation or stress
Surface is usually coated with carbon deposits, which must be removed using acid pickling
Cold rolling results in a material that has a tighter tolerance and better surface finish
State two features of gravity die casting
Process type: Redistribution
Lower melt point metals such as aluminium, aluminium alloys and zinc-based alloys
Relies on gravity to help the metal flow into the mould
Used for thicker mould sections
Used for very large-batch and mass production
State two features of pressure die casting (hot chamber)
Process type: Redistribution
Lower melt point metals such as aluminium, aluminium alloys and zinc-based alloys
Molten metal stored in a shot of molten metal is forced into the die
Fast process
Used for very large-batch and mass production
State two features of pressure die casting (cold chamber)
Process type: Redistribution
Lower melt point metals such as aluminium, aluminium alloys and zinc-based alloys
Molten metal ladled into shot chamber and hydraulically pushed into the chamber
Used for very large-batch and mass production
State two features of investment casting (lost wax casting)
Process type: Redistribution
Used for intricate or awkward shapes that would be difficult or impossible to mould using any other casting process
High quality, excellent finish
Wax patterns are cast from a master mould repeatable quality process
State two features of low temperature pewter casting
Process type: Redistribution
Used for school or college workshops
Can be used with a simple MDF mould
Suitable for one-off production or small batch (with aluminium moulds)