tutorial questions

Question 1

Current limitation of AM

Answer 1

• Selection of materials
• Material properties
• Resolution & Surface finish
• Throughput
• Post processing??
• Materials cost

Question 2

issues with stl

Answer 2

In summary; They cannot represent curves accurately, they have no scale to represent real world units, there is nothing to ensure they are completely solid.

Question 3

name the different types of Vat polymerisation

Answer 3

Stereolithography-Laser Stereolithography Projection Stereolithography

Micro-stereolithography
Two-photon polymerization

Question 4

Material extrusion-

Answer 4

A material is selectively dispensed through a nozzle

or orifice

Question 5

Selective Laser Sintering (SLS)

Answer 5

draw

Question 6

Advantages of Sintering

Answer 6

• Polymer powders are relatively easy to produce
• Parts produced have properties similar to injection moulded material
• Un-fused powder acts as the support mechanism – therefore no support
structures
• There are fewer H&S issues than with Vat Photopolymerisation processes
• Parts are tough and therefore suitable for functional testing
• Unused polymer powder material can be re-cycled and used in the build
process
• You can fill the whole build volume with parts
• Minimal post-processing (for polymers) – requires unsintered powder removal
• Highly complex bespoke geometries are achievable

Question 7

Powder bed fusion -

Answer 7

thermal energy selectively fuses regions of a powder bed.

Question 8

. Directed energy deposition

Answer 8

Focused thermal energy is used to fuse

materials by melting as the material is being deposited.

Question 9

Advantage of material jetting

Answer 9

• Advantages
• Good part edge quality
• High resolution (40µm features)
• Multimaterials possible
• Multiple heads print multiple materials
• Functionally graded materials
• Different mechanical properties
• Dissolvable support structures

Question 10

Disadvantages of material jetting

Answer 10

Disadvantages
• Limitations on the material properties
• No metals, ceramics
• However ink with fillers has been looked at in the research
environment with up to 40% ceramic particles.

Question 11

. Binder jetting

Answer 11

A liquid bonding agent is selectively deposited to join powder
materials.

Question 12

What is the infiltration process

Answer 12

Infiltration is the process of
applying a liquid resin to a
printed part to provide strength
and impart specific properties.

fill porosities
– Improve mechanical properties
– Ensure suitable thermal properties
– ease of use