کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4915262 1427735 2017 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Discrete element simulation and experimental study of powder spreading process in additive manufacturing
ترجمه فارسی عنوان
شبیه سازی عنصر گسسته و بررسی تجربی فرایند پخش پودر در تولید افزودنی
کلمات کلیدی
تولید افزودنی، روش عنصر گسسته، اسپری لیزری، چاپ سه بعدی، پخش پودر،
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
چکیده انگلیسی


- DEM simulation of the powder spreading process with application to laser sintering
- A higher spreader velocity increases the bed surface roughness and void fraction.
- A roller type spreader outperforms a blade spreader at the same operating conditions.
- Elongated particles in a prepared bed show shape segregation and alignment to the flow.

Powders used in additive manufacturing (AM) are spread onto a compact layer of particles for sintering and this process is repeated layer by layer to form the final products. Spreading of rod-shaped particles in realistic AM settings is simulated using the discrete element method (DEM) to investigate the effects of particle shape and operating conditions on the bed quality, characterised by its surface roughness and solid volume fraction. It is discovered that larger particle aspect ratios, Ar, or higher spreader translational velocities result in a lower bed quality, i.e. a larger surface roughness and a smaller volume fraction. The surface roughness increases monotonically with Ar. However, the volume fraction exhibits a maximum at Ar = 1.5 for randomly packed powder beds that are formed by the roller type spreaders moving at low translational velocities. It is also found that a roller outperforms a blade spreader in terms of the quality of the prepared bed at the same operating conditions. The micro-structural analysis of the beds also shows particle alignment in response to the induced flow, which is qualitatively confirmed by a set of purposely-designed experiments. In addition, a shape segregation is documented for powders with mixed aspect ratios (Ar) such that particles with larger Ar tend to accumulate on the upper layers of the bed.

Graphical Abstract158

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Powder Technology - Volume 306, January 2017, Pages 45-54
نویسندگان
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