Metal Additive Manufacturing

Question 1

Describe PBF (laser sintering)

Answer 1

1) a bed of metal powererd is set below a laser
2) laser traces the desired layer causing it to melt and form
3) build platform moves down and new powder is added for the next layer

Question 2

Describe PBF (eletron beam melting)

Answer 2

1) a bed of metal powererd is set below a laser
2) high energy eletron beam controlled by magnetic fields traces the surface casing it to melt
3) build platform moves down and new powder is added for the next layer

Question 3

What are the benifits of PBF (powder bed fusion) ?

Answer 3

Usage of exotic materials,
Reductes sub-assemblies,
Non-line of sight structures
(lattices, manifolds,
conformal cooling channels), Minimally constrained Topology Optimisation

Question 4

What are the Limitations of PBF (powder bed fusion) ?

Answer 4

powder must be removed
machining is unreliable
part size is limited
poor surface texture
requires several processes to create accurate parts

Question 5

Describe DED (blown powder)

Answer 5

1) powder is supplied into the path of a laser beam

2)the beam melts the powder fusing it to the part

3) the beam moves in the x,y,z directions to create a shape

4)an inert gas sheilds it from oxidation

Question 6

Describe DED (Wire Fed)

Answer 6

1) a hot wire is fed into a plasma beam
2) the wire melts onto the workpiece
3) an inert gas sheilds it from oxidation
4) computer controls plasma beam position

Question 7

What are the benifits of DED (Direct Energy Deposition) ?

Answer 7

Near Net Shape production for large parts
Adding features to work pieces is easy
usefule for Repairs and Reworking materials

Question 8

What are the Limitations of DED (Direct Energy Deposition) ?

Answer 8

Weldable metals only
causes anisotropic mechanical properties
creates thermally indusced distorisions
2.5 dimensional (only made of thick flat layers)