The surface roughness of the substrate itself could play an important role for the bonding at the interface. In this paper, a correlation of the surface roughness of a rigid alumina substrate and its 2D model of estimated surface area has been studied using Atomic Force Microscopy (AFM). With rougher surface, the adhesive strength between a deposited copper film and the alumina substrate is hig...

The purpose of this study was to investigate the effect of modifying aluminum oxide slips with magnesium oxide (MgO) to create a jointing material for In-Ceram Alumina. Jointed In-Ceram Alumina bars with In-Ceram Alumina slips containing 0-1.0 mass% MgO were examined by a three-point bending test. Joint-free bars were also tested as controls. Fracture surfaces were evaluated by scanning electro...

in this study, preparation of nano-sized gamma alumina with high specific surface area and high yield by thereaction between aluminum nitrate and sodium carbonate, without using any surfactant is reported. bohemite (aluminum oxyhydroxide) was prepared as a precursor by strict control of ph and reaction temperature. the gel produced was purified by washing followed by centrifugation. the specifi...

ÐCommercially available alumina of 94% nominal purity was used to examine the in ̄uence of loading rate on toughening mechanisms. For ®ne-grained alumina, the crack resistance, KR, was found to be independent of crack length and loading rate. Coarse-grained alumina exhibited strongly rising R-curves where the initial fracture toughness, K0, was found to be independent of the loading rate. The ne...

In previous work by the authors, aspects of the surface chemistry connected with methyl chloride synthesis over an η-alumina catalyst have been examined. This communication considers a role for Group 1 metal salts to modify the catalytic performance of the well characterised η-alumina catalyst. Firstly, based on a previously postulated mechanism for the reaction of methanol on η-alumina, a mech...

We present here a broadband, wide-angle, and polarization-independent nearly perfect absorber consisting of mirror-backed nanoporous alumina. By electrochemically anodizing the disordered multicomponent aluminum and properly tailoring the thickness and air-filling fraction of nanoporous alumina, according to the Maxwell-Garnet mixture theory, a large-area dark alumina can be made with excellent...

In this study a bioinspired approach to induce self-mineralization of bone-like material on alumina surfaces is presented. The mineralizing enzyme alkaline phosphatase (ALP) is covalently immobilized by a carbodiimide-mediated chemoligation method. The enzymatic activity of immobilized ALP and its mineralization capability are investigated under acellular conditions as well as in the presence o...

A novel process of fabricating various oxide nanostructures on glass substrates is described. Transparent porous alumina films ( 6–150 nm) were first formed in acid solutions by anodization of aluminum layers sputter-deposited on a glass plate coated with a tin-doped indium oxide film. The porous alumina structures after pore-widened were then used as a host or a template in a sol–gel process t...

Stainless steel particles (60 μm in mean diameter) cladded with an alumina shell (2 μm thick and manufactured by mechanofusion) were sprayed with an Ar-H2 (53-7 slm) d.c. plasma jet (I = 500 A, P = 28 kW, th = 56 %). Two main types of particles were collected in flight, as close as 50 mm downstream of the nozzle exit: particles with a steel core with pieces of alumina unevenly distributed at t...

Silica nanoparticles (NPs) belong to the industrially most important NP types. In a previous study it was shown that amorphous SiO(2) NPs of 12.5 and 27.0 nm are stable in algal growth inhibition assays and that their ecotoxic effects are related to NP surface area. Here, it was hypothesized and demonstrated that an alumina coating completely alters the particle-particle, particle-test medium a...