The effect of reactive sintering on the densification of boron carbide zirconium diboride composite

In this thesis, different additives (Zirconia, Zirconium Silicate, Carbon) are used to produce Boron Carbide/Zirconium Diboride (B4C/ZrB2) composite by Spark Plasma Sintering (SPS). Effects of different additives and sintering parameters (sintering temperature, sintering time, pressure, heating rate, etc.) on the densification of the composite is observed. Firstly, B4C/ZrB2 composite is produced by using B4C and ZrB2 powders via non-reactive sintering then different additives (ZrO2-ZrSiO4), as zirconium (Zr) source, are used to produce the same composite by reactive sintering, and effects of reactive sintering is observed. The relative density of the sample produced by B4C and ZrB2 powders at 2150 °C by 15.7 MPa pressure is %99.4734. When reactive sintering (samples produced by B4C and ZrO2 powders) is considered, the highest relative density (%97.2111) is achieved by sintering 15 minuteS at 2000 °C via 31.4 MPa pressure. The samples in which ZrSiO4 is the zirconium source, the highest relative density (%96.0524) is achieved by sintering 15 minutes at 2107 °C by 15.7 MPa pressure. Archimedes Method is used for relative density calculations, Scanning Electron Microscope (SEM) is used for microstructure observation and X-ray Diffraction analysis is used to observe phases that exist in produced parts. The positive effect of reactive sintering on the densification at lower temperatures is observed besides the importance of the contribution of the control on the phases and gases produced during reactive sintering is observed.