Corrosion Resistance of Aluminum Alloy AA2024 with Hard Anodizing in Sulfuric Acid-Free Solution.

In the aeronautical industry, Al-Cu alloys are used as a structural material in the manufacturing of commercial aircraft due to their high mechanical properties and low density. One of the main issues with these Al-Cu alloy systems is their low corrosion resistance in aggressive substances; as a result, Al-Cu alloys are electrochemically treated by anodizing processes to increase their corrosion resistance. Hard anodizing realized on AA2024 was performed in citric and sulfuric acid solutions for 60 min with constant stirring using current densities 3 and 4.

Environmental Levels, Sources, and Cancer Risk Assessment of PAHs Associated with PM and TSP in Monterrey Metropolitan Area.

In this work, the content of polycyclic aromatic hydrocarbons (PAHs) in total suspended particles and particulate matter with an aerodynamic diameter ≤ 2.5 µm (PM) was analyzed using gas chromatography-mass spectrometry. In addition, a sequential chemical analysis of C-rich particles was performed through the parallel coupling of micro-Raman spectroscopy and scanning electron microscopy with X-ray scattering detection.

Optimizing the Coverage Density of Functional Groups over SiO Nanoparticles: Toward High-Resistant and Low-Friction Hybrid Powder Coatings.

Hybrid powder coatings (HPC) with low friction and high hardness enhance the sliding speed and allow interlocking or meshing products to slide effortlessly within each other, saving energy. In automobiles, they decrease fuel consumption and greenhouse gas emission. In the present work, a new insight of the key role played by the coverage density of triethoxyphenylsilane (TPS) grafted to SiO nanoparticles over the friction coefficient, hardness, elastic modulus, and roughness of HPC is presented for the first time.