Aqueous Synthesis at 200°C of Sub‐10 Nanometer Yttria Tetragonally Stabilized Zirconia Using a Metal‐Ligand Approach

Abstract

The objective of this study was to produce well‐dispersed nanosized yttria tetragonally stabilized zirconia (Y‐TZP) powder in aqueous suspension. The Y‐TZP powder was produced by precipitation from homogeneous solution at 200°C under hydrothermal conditions. A homogeneous solution was created through the use of a complexing agent, which subsequently could be used in a dispersion scheme developed for the nanosized Y‐TZP powder. Characterization of the Y‐TZP powder was performed using X‐ray diffraction, Raman spectroscopy, X‐ray fluorescence, and high‐resolution transmission electron microscope. The overall goal of this study is the eventual production of bulk ceramics from well‐dispersed nanosized aqueous ceramic suspensions via wet processing techniques.

Pressureless Sintering t‐zirconia@δ‐Al2O3 (54 mol%) Core–Shell Nanopowders at 1120°C Provides Dense t‐Zirconia‐Toughened α‐Al2O3 Nanocomposites

“…Multiple additives are used to partially stabilize the tetragonal phase during processing. Yttria is the most common additive with 3 wt% typical for average grain sizes (AGSs)≥1 μm (3YPSZ, 1.6 unit mol%) 11–17 . The literature suggests that less yttria is required to partially stabilize finer grained ceramics 17,18 .…”

“…3YPSZ materials are used for applications ranging from multiple types of prosthetic implants, to ceramic knives, thin‐film electronic devices, photonic band gap devices, to auto exhaust catalysts 1–17 . Unfortunately, 3YPSZ undergoes unwanted phase transformation to the monoclinic phase in humid environments even at ambient conditions 18–21 .…”

Ceramics based on calcium hydroxyapatite synthesized in the presence of PVA

“…One such technique is to use surfactants, which modify the surface of particles [3], and to eliminate milling of the powder material, assuming formation from highly concentrated suspensions. A number of other techniques can also be used.…”

“…These samples were formed into 1.3 -1.5 g 3´6´40 mm bars under compaction pressure 50 -100 MPa. The relative density of the samples was calculated assuming the theoretical density of HAP to be 3.16 g/cm 3 .…”

“…Since the synthesis was conducted in air, CO 2 is inevitably trapped and enters the structure of HAP as CO 3 2-. Consequently, the further decrease of the mass could be due to release of CO 2 .…”