X-ray diffraction analysis of the yttria stabilized zirconia powder by mechanical alloying and sintering

In the present work, monoclinic zirconia was mechanically alloyed with yttria (6-14 mol%) via ball milling at the different ball-to-powder mass ratios (BPMRs) for 3-24 h, and then, the mixed powders were sintered at 1100 degrees C and 1500 degrees C. Line profile analysis of the X-ray diffraction (XRD) patterns, using the Alexander-Klug, Adam-Cox, Rietveld, and Scherrer methods, was systematically used to investigate the effects of the milling time, BPMRs, sintering temperature, sintering time and zirconia-to-yttria ratio. The experimental results indicate that the yttria-stabilized zirconia (YSZ) appears in the mixed powder after a milling time longer than 8 h. In addition, the ZrO2 content will decrease with the milling time or amount of BPMRs. The XRD patterns demonstrate that the intensity of the YSZ diffraction peaks was greatly improved after sintering. However, even if sintering at 1100 degrees C for 10 h, m-ZrO2 still remained in the mixed powder. When the temperature rose to 1500 degrees C, only the cubic phase of YSZ (c-YSZ) was found in the zirconia-14 mol% yttria powder. Based on the above results, combined with other related research, the possible mechanism of the phase transformation in the ball milling and sintering process is discussed in this paper.