| Summary: In this study, three different bulk samples of the purchased MgB2 powder is produced according to Ar gas pressure, temperature and time series. During the sinterization done for the production of bulk samples; the pressure of the gas, the temperature of sinterization and the duration of the process are searched to determine the structural, magnetic and mechanical effects on the bulk samples. According to our laboratory conditions the ideal duration of sinterization is determined for the development of superconductivity properties of these bulk samples. In our research, to determine its structural analysis of the samples X-ray diffraction method is used. For the magnetic properties, PPMS method is used for the determination of M-H and M-T conditions of bulk samples. For the mechanical properties of these bulk samples Vickers Micro hardness Analysis and Depth Sensitive Microhardness Method is used. From the Load-Displacement Graphics, the dynamic hardness values (Hd) of the samples are calculated with using Oliver-Pharr Method. From the X-ray Diffraction Analysis, main phase and impurity phases of the samples are defined. The critical temperature values (Tc) and critical current density (Jc) are calculated from M-T and M-H diagrams respectively.
During the structural properties investigation of the bulk MgB2 samples, it is observed that gas pressure applied during sinterization, temperature and duration of sinterization defines the phase content and phase formation in the bulk samples. It is also observed that the gas pressure applied during sinterization effects the bulk samples, during the increased sintering temperature MgB2 is decomposed so that it forms the impurity phases of the samples because of the evaporation property of Mg during this process. From the results of measurements, the most ideal sintering temperature is determined to be temperature ranges 800-850°C and sintering time is found to be 1-3 hours. During the research of mechanical properties, it is observed that there is a decrease in the Vickers microhardness values of the bulk samples while increase in sintering temperature and duration.
Keywords:MgB2, Sintering time, M-T Diagrams, M-H Diagrams, Critical Current Density (Jc), Vickers Microhardness Analysis, Dinamical Microhardness |
