The Change of X‐ray Diffraction Peak Width During in situ Conventional Sintering of Nanoscale Powders

Abstract

Diffraction peaks of nanoscale particles of 3 mol% yttria‐stabilized zirconia become sharper as the powder sinters. The reduction in the peak width is correlated with the increase in density. The sharpening of the peak agrees reasonably well with the remaining free surface area as the sample sinters. Therefore, high curvature of the free surface of the pores is assumed to lead to peak broadening (the grain boundaries that grow at the expense of the free surfaces of the pores do not have this curvature). The change in the grain size during sintering does not make a significant contribution to peak width.

Broadening of Diffraction Peak Widths and Temperature Nonuniformity During Flash Experiments

“…The present experiments were carried out on presintered experiments, since in sintering experiments there is a complication from the change in the peak width as powder particles evolve into contiguous grains. 12 h . Note that the broadening predicted at very high power levels is consistent with peak broadening in Stage III seen in Fig.…”

“…The present experiments were carried out on presintered experiments, since in sintering experiments there is a complication from the change in the peak width as powder particles evolve into contiguous grains …”

“…For dense specimens sintered for 3 h at 1450°C, the diffraction peak width has reached a constant minimal value which can be associated to instrumental errors . In the absence of microstructural effects, the origin of peak broadening is explained by temperature gradients within the sample.…”

“…For dense specimens sintered for 3 h at 1450°C, the diffraction peak width has reached a constant minimal value which can be associated to instrumental errors. 12 In the absence of microstructural effects, the origin of peak broadening is explained by temperature gradients within the sample. If different parts of the specimen are at different temperatures then they would render a diffraction peak at slightly different positions depending on the thermal expansion incurred in those parts.…”

“…The reason is that even in conventional sintering we have observed that the peaks from powders are considerably wider than in sintered specimens, and that these peaks narrow down while the sample sinters. 12 Therefore, it is difficult if not impossible to disentangle the diffraction data for peak-narrowing as powders convert into a dense body, and peak broadening arising from temperature gradients.…”