Yazar "Çalin, Recep" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • Küçük Resim
    Öğe
    Designing of a powder compressing device with vibration and investigation of compressibility of MgO powders with this device
    (Elsevier Sci Ltd, 2007) Çalin, Recep; Citak, Ramazan
    One of metal matrix composite (MMC) production methods is infiltration of liquid metal into preformed reinforcement. In this method, MMCs are produced by infiltration of liquid metal into preformed reinforcement using one of pressure, vacuum or pressureless (free) infiltration methods. For infiltration purposes, reinforcement materials in different figuration are preformed in desired shape and reinforcement volume ratio. In this study a vibration apparatus has been designed to compress the particulate reinforcement in a tube so that pressure or vacuum infiltration can be carried out. The compressibility of MgO powders with different sizes with this apparatus has also been investigated. It has been found that with this apparatus, it is possible to compress desired number of specimens uniformly at the same time and at the same ratio. It has also been determined that MgO powders can be compressed in different ratio due to particle sizes with this device. Compressing time of 3 min is enough to reach maximum compression ratio in MgO powders. (c) 2006 Elsevier Ltd. All rights reserved.
  • [ X ]
    Öğe
    INVESTIGATION ON THE WEAR BEHAVIOUR AND PROPERTIES OF RHA REINFORCED 7075 ALUMINIUM T6 COMPOSITES PRODUCED BY VACUUM INFILTRATION
    (Microscopy Society of Malaysia, 2022) Tanis, Naci Arda; Okur, Onur; Jafaar, Che Nor Aiza; Ariff, Azmah Hanim Mohamed; Çalin, Recep
    Aluminum matrix composites containing hard ceramic particles have higher strength, hardness and wear resistance than conventional materials. However, the high cost of hard ceramic reinforcements has led researchers to obtain ceramic reinforcement from organic wastes such as rice husk and eggshell, and they are looking for ways to increase the hardness and wear properties by reinforced these organic wastes. In this study, 1, 2, and 4 vol.% rice husk ash (RHA) were added to AA7075 metal matrix. Samples were produced in a steel tube under 550 mmHg vacuum at 750 °C for 3 minutes. T6 heat treatment (aging) was applied to the samples. The density, porosity, and hardness of non-aged and aged samples were measured and compared. In addition, SEM and EDS analysis of aged samples were performed and wear properties under 20 N load was investigated. While the hardness and the porosity of T6 heat treated composites increased with increasing reinforcement volume ratio, T6 heat treatment did not improve the hardness and the wear properties of the composites significantly compared to unreinforced (0 vol%) sample. Wear tests showed that the mass loss increased with the increment of reinforcement-volume ratio. Increasing RHA content resulted in worsening the wear behavior of composites because of the poor wettability of RHA particles. © 2022, Microscopy Society of Malaysia. All rights reserved.
  • [ X ]
    Öğe
    The effect of reinforcement ratio on the composite structure and mechanical properties in Al-MgO composites produced by the melt stirring method
    (Adcotec Ltd., 2011) Çalin, Recep; Pul, Muharrem; Çitak, Ramazan; Şeker, Ulvi
    In this study, Al- MgO metal matrix composites (MMC) were produced with 5 %, 10 % and 15 % reinforcement- volume (R-V) ratios by the melt stirring method. In the production of composites 99.5 % pure Al was used as the matrix and MgO powders with the particle size of -105 ?m were used as the reinforcement. For every R-V ratio; stirring was made at 500 rev/min at 750°C liquid matrix temperature for 4 minutes and the samples were cooled under normal atmosphere. Then hardness and fracture strengths of the samples were determined and their microstructures were evaluated by using Scanning Electron Microscope (SEM). In general, it was observed that the reinforcement exhibited a homogeneous distribution in horizontal direction. But there is a slight inhomogeneity in vertical direction. It was determined that the increase in the R-V ratio increased the porosity and also the hardness. As for the fracture strength, the highest strength was obtained with the 5 % MgO reinforced sample.