Thin alumina films have found applications in electronic circuits and cutting tools and have been recently explored as protective coatings against high temperature oxidation, but these studies have been relatively rare. In this study, amorphous alumina films 3.5 pm thick were produced by reactive sputtering on Co-30Cr-6Al-0.5Y coatings, using a pure aluminum target in Ar + 0 2 atmosphere. Isoth...

The paper reviews progress for a program of research on alumina ceramics processing, with particular reference to diffraction results achieved using tube x-rays, neutrons and synchrotron radiation. Outcomes from three related studies are examined. l Calcination of alumina hydrates to o-alumina via intermediate aluminas, including some new results indicating the co-existence of cubic and tetrago...

An efficient and green protocol for the synthesis of αaminonitriles derivatives by one-pot reaction of different aldehydes with amines and trimethylsilyl cyanides has been developed using natural alumina, alumina sulfuric acid (ASA), nano-γ-alumina, nanoalumina sulfuric acid (nano-ASA) under microwave irradiation and solvent-free conditions. The advantages of methods are short reaction times, h...

milk-based espresso coffee is one of the most popular beverages. foam is an essential quality characteristic for this beverage. foam formation and stability is mainly related to the milk composition. in this study the influence of three different concentrations of xanthan gum (0.05, 0.1 and 0.2 g dm-3) and three different temperatures (50, 60 and 70 °c) on foam stability were examined and exper...

Interpenetrating Al O /Al composites were created by liquid metal infiltration of alumina structures with three-dimensional periodicity produced by a robotic deposition method. Volume-averaged lattice strains in the alumina phase were measured by synchrotron X-ray diffraction at various uniaxial compression stresses up to 200 MPa. Load transfer was observed to occur from the aluminum to the alu...

Simple nanoporous alumina matrix modification procedure, in which the electrically highly insulating alumina barrier layer at the bottom of the pores is replaced with the conductive layer of the gold beds, was described. This modification makes possible the direct electron exchange between the underlying aluminum support and the redox species encapsulated in the alumina pores, thus, providing t...

BACKGROUND Numerous studies have reported that microgrooves on metal and polymer materials can affect cell adhesion, proliferation, differentiation and guidance. However, our knowledge of the cell activity associated with microgrooves on ceramics, such as alumina, zirconia, hydroxyapatite and etc, is very incomplete, owing to difficulties in the engraving of microgrooves on the hard surface of ...

Lanthanide (Ln3+) doping in alumina has shown great promise for stabilizing and promoting desirable phase formation to achieve optimized physical and chemical properties. However, doping alumina with Ln elements is generally accompanied by formation of new phases (i.e. LnAlO3, Ln2O3), and therefore inclusion of Ln-doping mechanisms for phase stabilization of the alumina lattice is indispensable...

This paper considers the degradation of alumina and zirconia toughened alumina vs. alumina for hip implants. The materials are as assumed to be load bearing surfaces subjected to shocks in wet conditions. The load is a peak of force; 9 kN was applied over 15 ms at 2 Hz for 800,000 cycles. The volumetric wear and roughness are lower for ZTA than for alumina. The long ZTA ageing did not seem to h...