The present study employed a tungsten pH microelectrode to the formation of trivalent chromium conversion (TCC) coatings on Al, AA 2024-T3 aluminum alloy and AZ91D magnesium in SurTec ChromitAL solutions. had sensitivity –60 mV/pH peak final values for pre-treated 2024 were 4.9 3.5, 4.3 4.1, 4.7 respectively. initial value is great importance influencing coating deposition-driven force thicknes...

The establishment of reliable correlations between the extend of damage and a sensor response using automated non destructive testing (structural health monitoring) is the first aim of the present paper. The second and its main aim is the estimation of the efficiency of different approaches of the fatigue crack prediction when scalar parameters are used to represent the signal-response. Investi...

We present the results of the first sensitive L band (3.4 μm) imaging study of the nearby young embedded cluster NGC 2024. Two separate surveys of the cluster were acquired in order to obtain a census of the circumstellar disk fraction in the cluster. We detected 257 sources to the mL ≤ 12.0 completeness limit of our ∼110 arcmin primary survey region. An additional 26 sources with 12.0 < L < 14...

The effects of chromate treatment on the corrosion of an aluminum/copper aircraft alloy were examined with a galvanic corrosion apparatus composed of two electrodes and a zero resistance ammeter. Combinations of pure Al, pure Cu, and AA2024-T3 electrodes were immersed in 0.1 M NaCl solution, which was saturated with air, O2 , or argon. Selection of electrode material or differential aeration re...

The viscoelastic response of pure Al and 7075 (AlZnMg) and 2024 (AlCuMg) alloys, obtained with a dynamic-mechanical analyzer (DMA), is studied. The purpose is to identify relationships between the viscoelasticity and fatigue response of these materials, of great interest for structural applications, in view of their mutual dependence on intrinsic microstructural effects associated with internal...

Three-dimensional residual stress mapping of an aluminum 2024-T3 arcan specimen, butt-welded by the friction stir technique, was performed by neutron diffraction. Results indicate that the residual stress distribution profiles across the weld region are asymmetric with respect to the weld centerline, with the largest gradients in the measured residual stress components occurring on the advancin...

A novel method, powder thixoforming, for net-shape forming of the particle-reinforced Aluminum matrix composites in semi-solid state has been proposed based on powder metallurgy combining with thixoforming technology. The microstructural evolution and phase transformations have been investigated during partial remelting of the 2024 bulk alloy, prepared by cold pressing of atomized alloy powders...

The present paper is concerned with the application of a “plasticity-induced” crack closure model to study fatigue crack growth under various load histories. The model was based on the Dugdale model but modified to leave plastically deformed material in the wake of the advancing crack. The model was used to correlate crack growth rates under constant-amplitude loading and then used to predict c...