Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

Browse

Filters

2022 - 20242

Settings

Language: search.filters.language.enSubject: search.filters.subject.Powder bed fusion

Search Results

Now showing 1 - 2 of 2
  • Article
    Citation - WoS: 3
    Citation - Scopus: 3
    Macroporous Polymer-Derived Ceramics Produced by Standard and Additive Manufacturing Methods: How the Shaping Technique Can Affect Their High Temperature Thermal Behavior
    (Elsevier B.V., 2024) Ahmetoğlu, Çekdar Vakıf; Kulkarni,A.; Semerci,T.; Vakifahmetoglu,C.; Pelanconi,M.; Bottacin,S.; Sorarù,G.D.; 01. Izmir Institute of Technology; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering
    This work proposes the processing of porous ceramic lattices via three polymer-derived ceramic routes, namely powder bed fusion and infiltration, fused filament fabrication and replica, and a direct replica of a foamed polymer. A common feature in the processing of these lattices is the use of the same polysilazane as the preceramic source for the Si-C-N-O network that builds up during ceramization. We adopted rotated cube, honeycomb and randomized cellular geometries as a matter of comparison for thermal exchange when an air flow is forced through the structures up to 1050 °C. The three procedural pathways are discussed in their limitations regarding geometry, polymer-to-ceramic conversion, high-temperature heat exchange performance and durability. In this regard, while rotated cube geometry results in the best thermal exchange and highest pressure drop, we show a correlation between chemical composition and high temperature oxidation of the Si-C-N-O network, possibly attributed to the selection of the processing routes. © 2024 The Authors
  • Article
    Citation - WoS: 8
    Citation - Scopus: 11
    Spreadability of Metal Powders for Laser-Powder Bed Fusion Via Simple Image Processing Steps
    (MDPI, 2022) Ahmetoğlu, Çekdar Vakıf; Hasdemir, Beyza; Ahmetoğlu, Çekdar Vakıf; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    This paper investigates the spreadability of the spherical CoCrWMo powder for laser- powder bed fusion (PBF-LB) by using image processing algorithms coded in MATLAB. Besides, it also aims to examine the spreadability dependence with the other characteristics such as powder size distribution, apparent density, angle of repose. Powder blends in four different particle size distributions are prepared, characterized, and spreadability tests are performed with the PBF-LB. The results demonstrate that an increase in fine particle ratio by volume (below 10 µm) enhances the agglomeration and decreases the flowability, causing poor spreadability. These irregularities on the spread layers are quantified with simple illumination invariant analysis. A clear relation between powder spreadability and 3D printed structures properties in terms of residual porosity could not be defined since structural defects in 3D printed parts also depends on other processing parameters such as spatter formation or powder size over layer height ratio.