9 Additive Manufacturing

Question 1

8. Describe the selective laser sintering process technology in additive manufacturing. What is the starting material?

Answer 1

Selective laser sintering begins with a bed of powder material, such as powdered metal.

The selective laser sintering process entails the movement of a laser beam sinters onto heat-fusible powders in sections corresponding to a CAD model geometry.

In which, one layer at a time is needed to produce a whole solid piece. Essentially, the start-off amount of loose heat-fusible powders is scanned by a laser sinister. The laser sinister, due to the digital instructions for the CAD, precisely heats the very specific sections in the loose powder layer, to fuse the powder together, thus making it solid.

Once the first layer is laser sinter scanned, a new layer of loose powder is added onto the preexisting powder (increasing the loose powder’s height/volume)

thus the total loose powder matches a height to then add another layer that can be laser sintered. Each layer will build a solid three-dimensional geometric shape.

Any powder that is not sintered is later poured out.

Question 2

9. Describe the fused deposition modeling process technology in additive manufacturing.

Answer 2

The fused deposition modeling also refened to as fused filament fabrication (fff)

can be described as;

the process in which a long wax of thermoplastic filament is extruded onto the existing part surface from a work head to complete each new layer.

A work head controls both the x direction and y direction throughout each layer;

which then moves vertically upward by a height equal to one layer in the z direction.

The extrudate is solidified and cold welded to the cooler part surface in about 0.1 seconds.

Lastly, the part is fabricated layer by layer from the base upward.

Question 3

10. The plastic parts fabricated by 3D printer is not as strong as parts fabricated by traditional plastic manufacturing processes such as extrusion, why?

Answer 3

Plastic parts fabricated by 3D printers are not as strong as palls fabricated by traditional plastic manufacturing processes such as extrusion, because;

3D printers produce the plastic parts layer by layer,

thus making the plastic part have a reduced strength compared to the plastic part’s extruded counterpart.

Extrusion builds their plastic parts as one solid unit which is what certifies the plastic part’s strength.

Question 4

11. What are some of the strengths of additive manufacturing that might make it attractive to use for parts production. Identify three.(3)

Answer 4

1 Complex three-dimensional geometric shapes

2 Multiple functions to be combined into one piece (as opposed to needing the extra step of assembly)

3 Requires the utilization of CAD models to fabricate parts.

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