Synthesis and characterization of Al₂O₃–ZrO₂ nanocomposite powder by sucrose process.

Beitollahi, A.; Hosseini-Bay, H.; Sarpoolaki, H.

Nanocrystalline alumina–zirconia powders were prepared by a modified chemical route using sucrose, polyvinyl alcohol (PVA) and metal nitrates followed by a post calcination process. The process involved dehydration of Al3 –Zr4 ions-sucrose–PVA solution to a highly viscous liquid which on decomposition process produced a black precursor material. The obtained precursor were then calcined at various temperatures: 1,050, 1,100, 1,150, 1,200 and 1,250 °C for different soaking times (1, 2, 4 h) in air. The formation of a nanocomposite composed of α-alumina (~20 nm) and tetragonal ( t) zirconia (~19 nm) crystallites were confirmed for the sample calcined at 1,200 °C for 2 h, based on our XRD and TEM results. However, for the samples calcined below 1,150 °C the composite formed were composed of metastable alumina ( γ, δ, θ) as well as t-zirconia phases. Interestingly, the zirconia phase retained its tetragonal structure for all the samples calcined above 1,050 °C. This is possibly related to the “size effect” and reduction of surface enthalpy of the zirconia crystallites surrounded by Al3 cations.

ZIRCONIUM oxide; ALUMINUM oxide; DISACCHARIDES; SOLUTION (Chemistry); VINYL polymers

Journal of Materials Science: Materials in Electronics, 2010, Vol 21, Issue 2, p130

0957-4522

Academic Journal

10.1007/s10854-009-9880-9