Materials Science and Engineering / Malzeme Bilimi ve Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/4719

Browse

Filters

2022 - 20232

Settings

Subject: search.filters.subject.Silicon carbide

Search Results

Now showing 1 - 2 of 2
  • Article
    Citation - WoS: 19
    Citation - Scopus: 19
    Processing of Polymer-Derived, Aerogel-Filled, Sic Foams for High-Temperature Insulation
    (Wiley, 2023) Zambotti, Andrea; Ionescu, Emanuel; Gargiulo, Nicola; Caputo, Domenico; Ahmetoğlu, Çekdar Vakıf; Santhosh, Balanand; Biesuz, Mattia
    Porous polymer-derived ceramics (PDCs) are outperforming materials when low-density and thermal inertia are required. In this frame, thermal insulating foams such as silicon carbide (SiC) ones possess intriguing requisites for aerospace applications, but their thermal conductivity is affected by gas phase heat transfer and, in the high temperature region, by radiative mechanisms. Owing to the versatility of the PDC route, we present a synthesis pathway to embed PDC SiC aerogels within the open cells of a SiC foam, thus sensibly decreasing the thermal conductivity at 1000 degrees C from 0.371 W center dot m(-1)K(-1) to 0.243 W center dot m(-1)K(-1). In this way, it was possible to couple the mechanical properties of the foam with the insulating ability of the aerogels.The presented synthesis was optimized by selecting, among acetone, n-hexane, and cyclohexane, the proper solvent for the gelation step of the aerogel formation to obtain a proper mesoporous colloidal structure that, after ceramization at 1000 degrees C, presents a specific surface area of 193 m(2)center dot g(-1). The so-obtained ceramic composites present a lowest density of 0.18 g center dot cm(-3), a porosity of 90% and a compressive strength of 0.76 MPa.
  • Article
    Citation - WoS: 9
    Citation - Scopus: 9
    Polymer-derived ceramic molten metal filters
    (Springer, 2022) Dizdar, Kerem Can; Kulkarni, Apoorv; Dışpınar, Derya; Soraru, Gian Domenico; Ahmetoğlu, Çekdar Vakıf; Semerci, Tuğçe
    This paper reports the synthesis and the performance of polymer-derived ceramic filters for molten metal filtration. Two different filter types were studied: foam filters produced from flexible polyurethane (PU) foams and additive manufacturing (AM) filters produced from thermoplastic polyurethane (TPU) cellular structure, and the results from all filter types were compared with that of the commercially used SiC foam filters. In both cases, the urethane-based polymeric template was impregnated with the preceramic solution, followed by pyrolysis. The produced ceramic components were then used to filter a molten Al alloy (A357), and the resulting Al samples were characterized for their mechanical properties. When filters were used, more reproducible and reliable mechanical properties were achieved compared to the samples obtained without any filtration. Among the different filters tested, the foam filters demonstrated better performance in comparison with the AM ceramic filters due probably to the three-dimensional interconnected porosity compared with the unidirectional cellular structure of the AM ceramic filters.