الفهرس 
ABSTRACT
Surface Roughness StudiesOnly 14 pages are availabe for public view
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Abstract
In this study, novel low-cost techniques are applied on the surface of Fused
Deposition Modeling (FDM) products to improve its surface roughness. The
developed techniques impinge a jet of hot air exit from a nozzle to FDM
surfaces. The hot air locally melts the staircase on the surface and leaves it
smoother by the effect of sintering phenomenon. Two techniques are
employed by impinging the hot jet after manufacturing and within
manufacturing. Accordingly, the process introduces three main parameters:
air jet temperature; air jet velocity; and nozzle translational velocity over the
part surface. An experimental test rig was constructed to evaluate the
polishing process and its parameters using surfaces with average pre
processed Ra values of 7.5∓0.5 μm. Pumping hot air after manufacturing
shows significant and reproducible improvements in surface roughness
inherent with a glossy surface; whereas, an average reduction ratio up to
88% was reached which corresponds to Ra of 0.85 μm. In other hand,
pumping hot air within manufacturing shows no improvement in surface
roughness but it possibly improves part mechanical properties. Furthermore,
It was found that there is an allowable range of nozzle translational velocity
for every combination between jet velocity and jet temperature; otherwise,
lower nozzle velocity than allowable causes overheating and surface
deterioration. In addition, the study investigates these deterioration
phenomena, the defects in FDM part surfaces, and evaluated different
process parameters. Moreover, it was observed that surface defects are
reduced in the polished surfaces. For a concise conclusion, it is found that
the condition of low jet velocity and high jet temperature gives the best
polishing results over the allowable nozzle velocities.