additive manufacturing

additive manufacturing

build up parts by adding material

process of sintering

1. mould filled with metal powder

2. powder is placed under pressure, and heated to below the melting point of metal

3. pressure + heat makes the powder particles fuse together where they touch

4. 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

1. 3D CAD created, in which the part is broken down into layers

2. first polymer (ABS, PLA, Polyamides, Nylon) layer melted by printing head, so it sits on the base. It’s 225 degrees

3. head rises by 1 layer and adds the next polymer layer

4. repeat, then finished item removed

sterolithography

1. Computer breaks down 3D CAD drawing into layers (STL file)

2. each layer is a few micrometres thick

3. moveable platform is in a resin tank. This resin is a liquid polymer

4. the laser creates the product layer by layer, and the resin goes hard where the laser is

5. moveable part lowered each layer

6. repeat, unhardened resin drained