Effects of aging on the phase transformation and sintering properties of coprecipitated Al₂O₃-ZrO₂ powders

Effects of aging on the phase transformation and sintering properties of coprecipitated Al₂O₃-ZrO₂ powders

In this study, the effects of aging on the crystalline phases, crystallite sizes and sintering properties of coprecipitated Al₂O₃- ZrO₂ powders are investigated using thermogravimetry (TG), differential thermal analysis (DTA), X-ray diffractometry (XRD), dilatometry, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Coprecipitated Al₂O₃- ZrO₂ powder aging in the solution promoted the dissolution and reprecipitation process, which resulted in the boehmite structure subsequently transforming into bayerite. The densification and microstructural development of the coprecipitated Al₂O₃-ZrO₂ powders were dependent upon the aging time which shifted the θ→α-Al₂O₃ phase transformation to a higher temperature, lowered the crystallite growth rate, and prevented the occurrence of intragranular ZrO₂ particles during sintering.

In this study, the effects of aging on the crystalline phases, crystallite sizes and sintering properties of coprecipitated Al₂O₃- ZrO₂ powders are investigated using thermogravimetry (TG), differential thermal analysis (DTA), X-ray diffractometry (XRD), dilatometry, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Coprecipitated Al₂O₃- ZrO₂ powder aging in the solution promoted the dissolution and reprecipitation process, which resulted in the boehmite structure subsequently transforming into bayerite. The densification and microstructural development of the coprecipitated Al₂O₃-ZrO₂ powders were dependent upon the aging time which shifted the θ→α-Al₂O₃ phase transformation to a higher temperature, lowered the crystallite growth rate, and prevented the occurrence of intragranular ZrO₂ particles during sintering.