additive manufacturing
build up parts by adding material
process of sintering
mould filled with metal powder
powder is placed under pressure, and heated to below the melting point of metal
pressure + heat makes the powder particles fuse together where they touch
higher pressure/temperature, higher strength
Pros and cons of sintering
pros:
creates solid metal products, and doesnt use as much energy as casting (melting metal)
create products from different powders, where the metals wouldn’t mix properly molten
allows air gaps, so products are lower density than solid metal
cons:
requires lots of material
expensive
Pros and cons of rapid prototyping (3D printing)
Pros:
parts are made in 1 operation from a 3D CAD drawing
can quickly make complex parts that can’t be made with regular manufacturing
you can quickly tell if a part is suitable for the space available
Cons:
limited range of materials (certain polymers, flour, glue)
rapid prototyping for metal is being developed
material may not have the same properties as the desired material
some intricate parts may be easier made in conventional manufacturing
Fused deposition modelling
3D CAD created, in which the part is broken down into layers
first polymer (ABS, PLA, Polyamides, Nylon) layer melted by printing head, so it sits on the base. It’s 225 degrees
head rises by 1 layer and adds the next polymer layer
repeat, then finished item removed
sterolithography
Computer breaks down 3D CAD drawing into layers (STL file)
each layer is a few micrometres thick
moveable platform is in a resin tank. This resin is a liquid polymer
the laser creates the product layer by layer, and the resin goes hard where the laser is
moveable part lowered each layer
repeat, unhardened resin drained