Materials Research Express (Jan 2021)
Low-calcination temperatures of magnesia partially stabilized zirconia (Mg-PSZ) nanoparticles derived from local zirconium silicates
Abstract
Partially stabilized zirconia (PSZ) exhibits excellent physical, mechanical, electrical, chemical, thermal, and bioactive properties. Therefore, it is frequently used as a material for thermal barrier coatings, refractories, oxygen-permeating membranes, dental and bone implants. In this study, magnesia-partially stabilized zirconia nanoparticles were successfully prepared from zirconium silicates and MgSO _4 assisted with PEG-6000 via a facile templating method. The MgO concentration was varied from 1%–10% in wt% of ZrO _2 . Zirconium silicates were initially converted to Zr-precursor solution, exhibiting pH 3. Then, the appropriate amount of the Mg-precursor was mixed with the proper amount of the Zr-precursor solution. A 10%(w/v) PEG-6000 solution was added into the PSZ precursor solution at a ratio of the precursor-to-PEG volumes of about 15:1 under stirring and heating, resulting in a very fine white gel. The gel was filtered, dried, and then calcined at elevated temperatures of 600, 800, and 1000 °C. The characteristics of the final product were then evaluated. According to the experimental results, the MgO concentration influences the ZrO _2 phase transformation at elevated calcination temperatures. In this study, the lower the MgO dopant concentration added into ZrO _2 , the more stable the t- ZrO _2 phase in PSZ samples at high temperatures. However, the MgO presence is detected as periclase in all samples with a very low peak intensity at elevated calcination temperatures. The obtained PSZ samples consist of nanoparticles and high agglomeration, some of particles exhibit elongated and rod-like shapes. The PEG existence during the PSZ preparation has restrained particle interaction and aggregation of the as-synthesized PSZ samples, leading to PSZ nanoparticles evolution.
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