Influence of sintering temperature on microstructural evolution of spark plasma sintered Inconel738LC

摘要

This work studied the effect of processing temperature on the microstructure of sintered Inconel 738LC nickel-based superalloy processed via spark plasma sintering technology. The processing parameters used were, 50Mpa pressure, 5minuts holding time and 100 ?C/min heating rate, with the sintering temperature varied over three different temperatures at 1000, 1100 and 1200 °C. Inconel 738LC powder was mix at the same proportion for all the samples and under the same condition. Test samples were fabricated from the admixed powders and the influence of sintering temperature on the microstructure, porosity and fracture toughness was characterized. Scanning electron microscope (SEM-EDS) was used to investigate the bulk morphology of the sintered alloy, the phases present within the bulk volume of the fabricated samples was investigated, using energy dispersive X-ray diffraction spectroscopy (XRD). From the result analyzed, the increase in sintering temperature lead to a reduction in porosity, decrease in fracture toughness and increase in hardness value. Increase in sintering temperature had positive impact on the sintered alloy, by reducing the level of porosity present in the sintered samples. There is a reduction in the fracture toughness value of Inconel 738LC, this is expected due to the increase in hardness property.