Additive, joining and finishing processes Flashcards
(9 cards)
What is 3d printing
3D printing uses a computer model to manufacture a complex 3 dimensional component from thermoplastic polymer
Process for 3d printing
pla or abs plastic is supplied to the heated extruder unit from a spool of thin filament
the extruder melts the filament and forces it out the nozzle at 190-285 degrees C
Each slice of the model is recreated as a 2d layer of extruded polymer deposited from the nozzle
More layers are added until the shape is complete
What is brazing
Brazing uses a brass alloy to bond or stick two components together.
What is MIG and MAG welding
Both use an electric arc to provide heat to melt metal
Both use a spool of filler matching the component metal that is fed into the welding pool
A shielding gas is used to prevent oxidation of the weld pool (no flux)
MIG uses a pure argon and is used for non ferrous metals
MAG uses a mix of argon and carbon dioxide, and is used for welding steel
What is riveting
Riveting is a method of permanently joining two or more overlapping metal sheets or plates. Riveting can be used to join dissimilar metals
Type of rivets
Hammered rivets, Hot rivets, Pop rivets
What is mechanical fastening
Mechanical fasteners allow components to be joined together. This can be undone to allow for products to be disassembled.
What is painting and powder coating
Painting:
Conventional wet paint contains coloured pigments carried in water or oil based solvent, which evaporates into the atmosphere as the paint dries. Must be done ina well ventilated area. Can be brushed or sprayed on
Powder coating:
Applies a highly durable protective layer of polymer onto metal components without releasing solvent into the atmosphere.
How to do powder coating
The metal component and dry powder are oppositely charged
This causes the fine powder to be attracted to the metal and form an even coat
Coated components move through an oven where powder particles melt and fuse together
