Mechanical Engineering / Makina Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/4129

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  • Article
    Citation - WoS: 54
    Citation - Scopus: 62
    Sic-Particulate Aluminum Composite Foams Produced by Powder Compacts: Foaming and Compression Behavior
    (Springer Verlag, 2003) Elbir, Semih; Yılmaz, Selahattin; Toksoy, Ahmet Kaan; Güden, Mustafa; Hall, Ian W.
    The foaming behavior of SiC-particulate (8.6% by volume) aluminum composite powder compacts contained Titanium Hydride blowing agent was investigated by heating above the melting temperature (750°C) in a pre-heated furnace. Aluminum powder compacts were also prepared and foamed using similar compaction and foaming parameters in order to determine the effect of SiC-particulate addition on foaming and compression behavior. The linear expansions of the compacts at various furnace holding times were ex situ determined. Optical and scanning electron microscopy techniques were used to characterize prepared and deformed foams microstructures. The SiC-particulate addition was found to increase the linear expansion and reduce the extent of the liquid metal drainage and cell coarsening of the aluminum compacts. The composite foam samples also showed higher compressive stresses, but a more brittle behavior as compared with aluminum foams.
  • Article
    Citation - WoS: 55
    Citation - Scopus: 61
    Sic-Particulate Aluminum Composite Foams Produced From Powder Compacts: Foaming and Compression Behavior
    (Springer Verlag, 2006) Güden, Mustafa; Yüksel, Sinan
    The foaming behavior of SiC-particulate (SiCp) aluminum composite powder compacts containing titanium hydride blowing agent was investigated by heating to 750°C in a pre-heated furnace. Aluminum powder compacts were also prepared and foamed using similar compaction and foaming parameters in order to determine the effect of SiCp-addition on the foaming and compression behavior. The SiCp-addition (10 wt%) was found to increase the linear expansion of the Al powder compacts presumably by increasing the surface as well as the bulk viscosities. The compression tests conducted on Al and 10 and 20% SiCp foams further showed a more brittle compression behavior of SiCp/Al foams as compared with Al foams. The collapse stresses of Al and 10% SiCp/Al foams were also predicted using the equations developed for the open and closed cell foams. Predictions have shown that Al foam samples behaved similar to open cell foams, while 10% SiCp/Al foam collapse stress values were found between those of open and closed cell foams, biasing towards those of the open cell foams.
  • Article
    Citation - WoS: 11
    Citation - Scopus: 14
    Quasi-Static and Dynamic Compression Behaviour of an Fptm Alumina-Reinforced Aluminium Metal Matrix Composite
    (Springer Verlag, 1998) Güden, Mustafa; Hall, Ian W.
    An aluminium metal matrix composite reinforced with continuous unidirectional α-alumina fibres has been compression tested at quasi-static and dynamic strain rates. In the transverse direction, the composite showed increasing flow stress (at 5% strain) and maximum stress within the studied strain rates, 10−3−3 × 103 s−1. In the longitudinal direction, the maximum stress of the composite increased similarly with increasing strain rates within the range 10−5−7 × 102 s−1. It is shown that, if brooming of the sample ends can be suppressed, the failure stress of the composite in longitudinal compression increases significantly. Metallographic observations reveal the typical modes of damage initiation in the composite.
  • Article
    Citation - WoS: 30
    Citation - Scopus: 33
    Processing and Compression Testing of Ti6al4v Foams for Biomedical Applications
    (Springer Verlag, 2009) Dizlek, Mustafa Eren; Güden, Mustafa; Türkan, Uğur; Taşdemirci, Alper
    Open cell Ti6Al4V foams (60% porosity) were prepared at sintering temperatures between 1,200 and 1,350 °C using ammonium bicarbonate particles (315–500 μm) as space holder. The resulting cellular structure of the foams showed bimodal pore size distribution, comprising macropores (300–500 μm) and micropores (1–30 μm). Compression tests have shown that increasing sintering temperature increased the elastic modulus, yield and compressive strength, and failure strain of foams. The improvements in the mechanical properties of foams prepared using smaller size Ti64 powder with bimodal particle distribution were attributed to the increased number of sintering necks and contact areas between the particles. Finally, the strength of foams sintered at 1,350 °C was found to satisfy the strength requirement for cancellous bone replacement.