Modifications of the properties of a porcelain through the addition of niobium pentoxide (Nb2O5)

There is a gap in the literature regarding the influence of Nb2O5 on traditional ceramic masses. Thus, this work promoted the addition of different proportions of this oxide in a porcelain composition in order to verify its effect on physical and microstructural properties. It was found that the addition of Nb2O5 reduced the apparent porosity of the composition at lower temperatures. The composition containing 5% in weight reached the characteristics of a porcelain at 1220 degrees C and the others reached these properties at 1240 degrees C. In addition, the secondary mullite obtained was in the form of more refined needles, although this characteristic has not statistically influenced the mechanical strength and the pyroplasticity index. The addition of Nb2O5 caused darkening of the pieces due to the reduction of material absorption in the visible region. The results of chemical microanalysis by Energy Dispersive X-ray Spectroscopy (EDS) and X-ray diffraction (XRD) indicated that crystals of Nb2O5 was found to be dispersed in the glass phase, without the formation of a new crystalline phase.