• MakaleAçık Erişim2017Scopus SJRQ3
    The Effect of Porosity and Cu Rate on Microstructure and Mechanical Properties of Co Alternative Powder Metallurgy Compound

    Çelik, Ertugrul; Aslan, Ali Kemal

    Cu-Ni-MX1480 powder compound were prepared at six different alloy ratios and cold pressed with a pressure of 300 MPa. Then 12 samples were obtained by hot pressing at 700 degrees C with 20 MPa pressure and at 800 degrees C with 30 MPa pressure for 4 minutes in a vacuum atmosphere hot pressing machine. Porosity ratios of samples were calculated by the different between theoretical density and measured density of samples. Effect of porosity on microstructure and mechanical properties were investigated by performing SEM, XRD, hardness measurements and TRS tests. It was observed that as a result of increased hot pressing parameters and increased Cu ratio, porosity ratio was decreased and better mechanical properties achieved.

    AtıfWoS15OpenAlex14
    Web of Scienceİncele
  • MakaleYalnız künye2014Scopus SJRQ2
    PRODUCTION OF MATRICES WITH MOLYBDENUM AS AN ALTERNATIVE TO MATRICES WITH COBALT IN DIAMOND CUTTING TOOLS

    Çelik, Ertugrul; Islak, Serkan; Ilkiliç, Cumali

    This study is about the production of new matrices that are an alternative to cobalt matrices in diamond cutting tools. Thus, Fe, Cu, Al2O3 and Mo were used as the matrix components. The mass fractions of 1 %, 2 % and 3 % Mo were added to the matrix. The production of matrices was performed in a fully automatic hot-pressing machine under 35 MPa of pressure, at a sintering temperature of 850 degrees C, with a dwell period 4 min. The microstructures and phase compositions of the matrices were established with a scanning electron microscope (SEM-EDS) and an X-ray diffractometer (XRD). The hardness and bending strength of the segments were determined. The transverse rupture strength (TRS) of the segments was determined using the three-point bending test. The results revealed that Mo increased the bending strength and hardness of the segments.

    AtıfWoS4
    Web of Scienceİncele
  • MakaleYalnız künye2013Scopus SJRQ3
    Microstructure and mechanical properties of PM Fe-Cu-Al2O3 alloys

    Çelik, Ertugrul; Islak, Serkan; Kir, Durmus; Ilkiliç, Cumali

    The purpose of this study was to investigate the effect of Cu addition on the microstructure and mechanical properties of PM Fe-Cu-Al2O3 alloys produced using hot-pressing method. Copper powder was added to iron powder at 5 wt.%, 10 wt.% and 15 wt.% rates. Production of Fe-Cu-Al2O3 alloys was carried out under pressure of 35 MPa, at 750, 800 and 850 degrees C, and for a sintering time of 4 minutes. Microstructure phase composition, relative density, hardness, and transverse rupture strength of the alloys were investigated. Phase composition and microstructure of the alloys were characterised by optical microscopy, X-ray diffraction and scanning electron microscope (SEM-EDS) techniques. The transverse rupture strength (TRS) of the samples was assessed by means of a three-point bending test. Hardness of Fe-Cu-Al2O3 alloys changed between 57 HB and 110 FIB depending on the amount of Cu and sintering temperature. Results show that the TRS of the alloys decreased together with the increase in the amount of copper, while it increased with increasing sintering temperature.

    AtıfWoS2
    Web of Scienceİncele
  • MakaleAçık Erişim2012Scopus SJRQ3
    Effect of the cBN Content and Sintering Temperature on the Transverse Rupture Strength and Hardness of cBN/Diamond Cutting Tools

    Kir, Durmus; Islak, Serkan; Çelik, Halis; Çelik, Ertugrul

    The aim of this work was to investigate the effect of cBN content and sintering temperature on the transverse rupture strength (TRS) of cBN/diamond cutting tools produced by hot pressing. The segments containing different cBN content were manufactured under 35 MPa pressure at 600, 650 and 700 degrees C with a 3 minutes sintering time. The TRS of segments were determined using three-point bending test. Microstructure and phase composition of fracture surface of segments were determined by scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. The obtained results show that the TRS of the segments with cBN were higher than that of the segments with diamond.

    AtıfWoS20OpenAlex16
    Web of Scienceİncele