Investigation of the effect of molding and sintering parameters on properties of powder injection molded steatite ceramics

In this study, steatite, which is known as one member of the advanced techonology ceramics, is produced by the method of Powder Injection Molding. Torque and capillary reometer experiments were performed for four different feedstocks. These experiments are used in injection molding for the ideal determined feedstock. Flow behave index, melt flow index, fluency and optimum loading ratios are determined seperately for all the feedstocs. Feedstock which contains 58% steatite+PEG8000/PP/SA by volume, for 200 0C temperature, displays the best reological properties. These properties are determined as flow behave index (0,507), fluency (8,99x10-3Pa-1s-1), melt flow index (988 g/dk.).Solvent and thermal debinding techniques are applied to the molded specimens.Thermal debinding parameters (TGA/DSC/DTA) are determined by thermal analysis.Sintering is applied between 1200-1300 0C for 2-4 hours. Theoritical density of 99,9% is obtained for 1300 0C temperature and 4 hours sintering time. Mechanical properties of the sintered specimens are determined by the method at three-point bending and tensile testing. Increasing strenght of the specimens are observed by the increasing density. Effect of injection and debinding parameters to surface and innternal cracks are investigated.Combined analysis is performed by XRD and elemental analysis by EDS. Determination of porosity is made by optic and SEM microscope besides grain size, grain boundary and grain structure and indeces by TEM.