Spreadability and characterization of metal powders for additive manufacturing
Başlık:
Spreadability and characterization of metal powders for additive manufacturing
Yazar:
Hasdemir, Beyza, author.
Yazar Ek Girişi:
Fiziksel Tanımlama:
xi, 56 leaves: color illustrarions, charts;+ 1 computer laser optical disc.
Özet:
Powder Bed Fusion (PBF) is one of the Additive Manufacturing (AM) techniques, in which metal powders are used as feedstock. AM process enables the production of lightweight structures, design freedom in 3D printed parts, short cycle time, etc. AM made part properties are affected by the powder characteristics used to form the component. A part comprises hundreds of spread layers; however, a homogeneous layer is crucial for obtaining the necessary final part properties. Spreadability can be defined as a method to quantify the powder distribution through the layer. Although it has not been standardized yet, currently, it is merely controlled by following the powder flowability, a standardized characterization method for AM. This thesis investigates the spreadability of the utilized powders for AM (here only Laser-Powder Bed Fusion will be used), with the image processing algorithms in MATLAB. Besides, it also aims to examine the spreadability correlation with the other characteristics such as flow rate, apparent density, angle of repose, and thus the final 3D printed components. Samples in six different particle size distribution were characterized, and spreadability tests were performed with the L-PBF machine. The powder characterization results demonstrated that an increase in fine particle ratio by volume (below 20 µm) enhances the angle of repose (AOR). The tests demonstrated that irregularities on the spread layer could be quantified with the image processing algorithms. The 3D printed samples were found porous. The reason for porosity in the sample might base on a combination of various factors, poor spreadability, spatter formation, and other L-PBF processing parameters might be the reasons for such microstructural development.
Konu Başlığı:
Yazar Ek Girişi:
Tüzel Kişi Ek Girişi:
Tek Biçim Eser Adı:
Thesis (Master)--İzmir Institute of Technology: Materials Science and Engineering.
İzmir Institute of Technology: Materials Science and Engineering--Thesis (Master).
Elektronik Erişim:
Access to Electronic Versiyon.