The rapid development of the global aluminum industry has led to a considerably increasing consumption of bauxite, from which alumina is mostly produced. Many aluminum producing countries including China have to import bauxite to keep the growth of native industry due to the low quality of bauxite. The costs of alumina production as well as the other aluminum-related products are correspondingl...

The reaction of γ-alumina with tetraethylorthosilicate (TEOS) vapor at low temperatures selectively yields monomeric SiO(x) species on the alumina surface. These isolated (-AlO)3Si(OH) sites are characterized by PXRD, XPS, DRIFTS of adsorbed NH3, CO, and pyridine, and (29)Si and (27)Al DNP-enhanced solid-state NMR spectroscopy. The formation of isolated sites suggests that TEOS reacts preferent...

The fracture rate of third-generation ceramic liners is greatly reduced compared with first- and second-generation liners because of improvements in the design and manufacturing process. Fractures of the alumina-bearing couple are rare for the same reason.This article describes a case of a fracture of an alumina-bearing couple delta ceramic liner without trauma history that was treated with cer...

Microsilica, or silica fume, is an amorphous type of silica mostly collected as byproduct of the silicon and ferrosilicon alloy production. In this work, low shrinkage alumina-mullite ceramic composites were prepared from mixtures of calcined alumina, silica fume and aluminum metal powder and sintered at 1550 o C for 2 hrs. The influence of silica fume and aluminum powder on the densification p...

In this study, we examined the fine structure of the compound eyes of a household fly and precisely replicated its entire structure using a low-temperature atomic layer deposition technique. The surface of the fly eye is found to be covered by highly packed protuberances, which potentially increases visual efficiency through increased photon capture for a given stimulus. The alumina replica was...

We compared and quantified the modes of failure and patterns of wear of 11 Mittelmeier and 11 Ceraver-Ostal retrieved alumina-alumina hip prostheses with reference to the corresponding clinical and radiological histories. Macroscopic wear was assessed using a three-dimensional co-ordinate measuring machine. Talysurf contacting profilometry was used to measure surface roughness on a microscopic ...

Zirconia-toughened alumina (ZTA) is of growing importance in a wide variety of fields exemplified by ZTA prosthetic implants. Unfortunately, ZTA composites are generally difficult to process because of the need to preserve the tetragonal zirconia phase in the final dense ceramic, coincident with the need to fully densify the a-Al2O3 component. We report here that liquid-feed flame spray pyrolys...

Three different alumina sources (boehmite, aluminium nitrate and α-alumina particles) 12Ce-TZP powder containing 1 wt% lanthanum oxide were used to prepare 12Ce-TZP-based alumina-toughened-zirconia (ATZ) composites. The obtained ATZs had similar density phase composition, whereas the microstructures significantly different. Alumina-particle addition gave rise a typical ATZ microstructure consis...