Fused Deposition Modeling (FDM): Do FDM systems extrude molten thermoplastic through a nozzle to deposit layers that match the part’s sliced cross-sections?
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ACorrect
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BIncorrect
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COnly for photopolymer resins
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DOnly when supports are unnecessary
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EValid only for metal 3D printing
Answer
Correct Answer: Correct
Explanation
Introduction / Context:Fused Deposition Modeling (FDM), also called Material Extrusion, builds parts by heating and extruding thermoplastic filament (e.g., ABS, PLA, PC, nylon) through a nozzle and placing material along toolpaths derived from sliced cross-sections. The statement correctly describes FDM's core mechanism.
Given Data / Assumptions:
- Thermoplastic filament is available in a controlled diameter.
- Nozzle temperature exceeds polymer softening point; cooling solidifies layers.
- Slicing software generates per-layer toolpaths and support structures if needed.
Concept / Approach:Each layer adheres to the previous via thermal bonding. Parameters like extrusion temperature, flow rate, layer height, and raster orientation affect strength, porosity, and surface finish. Supports or breakaway/soluble structures may be required for overhangs.
Step-by-Step Solution:
Import CAD and slice into layers; generate nozzle paths.Heat filament; extrude beads following perimeters and infill patterns.Cool to solidify; move Z to the next layer and repeat.Remove supports; perform any post-processing (sanding, annealing).Verification / Alternative check:Cross-sections reveal characteristic bead tracks and anisotropic properties (stronger in-plane than across layers), consistent with deposition mechanics.
Why Other Options Are Wrong:Photopolymer resins and metal powder processes correspond to SLA/DLP or PBF/DED, not FDM. Supports are often needed; FDM is not limited to support-free geometries.
Common Pitfalls:Incorrect temperatures causing poor adhesion; insufficient cooling on bridges; ignoring moisture in hygroscopic filaments leading to bubbles/stringing.
Final Answer:Correct