The effect of Opuntia ficus-indica (Nopal) as green corrosion inhibitor for carbon steel in 1 M HCl solution has been investigated by using weight loss tests, potentiodynamic polarization curves, and electrochemical impedance spectroscopy measurements. Also, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) analysis were performed. The inhibitor concentrations used ranged from 0 to 300 ppm at 25, 40, and 60 ∘ C. Results indicated the inhibition efficiency increases with increasing extract concentration and decreases with the temperature, and the inhibitor acted as a cathodic-type inhibitor which is physically absorbed onto the steel surface. In fact, the adsorption of the inhibitor on the steel surface follows the Langmuir adsorption isotherm, indicating monolayer adsorption. The presence of heteroatoms such as C, N, and O and OH groups were responsible for the corrosion inhibition.

No abstract

The 2xxx series aluminium alloys are important advanced functional materials due to their high yield strength, good fracture toughness and excellent fatigue properties [1]. Due to the extremely important role that the 2xxx series aluminum alloys play in the aviation industry, much attention has been devoted to understanding their structures and properties [1][2]. Particularly, comprehensive investigations have been made to elucidate the morphological dependence of the precipitates on material composition, thermal treatment history, and impurity elements to optimize the materials performance for designed applications [1][2].By another hand, in the last decades, the use of metallic matrix composites of two or more different metals, intermatallic compounds or second phases has been researched widely. They are produced by controlling the properties of the constituent phases, their relative amount, dispersed phase geometry including particle size, shape and orientation in the matrix to achieve optimum combination of microstructural and mechanical properties [3, 4]. Reinforcing particle such as SiC, Al 2 O 3 , and MgO, have emerged as a potential alternative for conventional aluminum-base composites because of their high mechanical properties. Additionally, because the effects on microstructure, mechanical properties, electrical conductivity and corrosion resistance the use of rare earth, especially La, Ce, Nd, Y and Sc have called attention, recently. Thus, the present work evaluates the effect of CeO 2 nanoparticles on the microstructure, precipitation sequence and hardening mechanisms of the Al 2024 alloy.A compound of Al-16.66% by weight of CeO 2 (CMAlCeO 2 ) was prepared by mechanical milling (Fig.1). Subsequently, the CMAlCeO 2 was added in proportions of 0.1, 0.5,3 and 5 wt. % of CeO 2 to the Al 2024 alloy by conventional casting. Finally, the material obtained was extruded and aged. The characterization of CMAlCeO 2 suggests a reaction of the chemical reduction of CeO 2 and the formation of a layer of Al 2 O 3 that covers the elemental Ce during the process (Fig.2). On the other hand, the hardness tests indicate that the lower content of CMAlCeO 2 (0.1, 0.5% weight of CeO 2 ) obtained hardness superior to the commercial alloy Al 2024 . In addition, the preparation of the CMAlCeO 2 composite material by powder metallurgy is an alternate route for homogeneously dispersing CeO 2 nanoparticles in an aluminum matrix. However, long sintering times are not recommended since this favors the formation of elongated Ce rich phases.

No abstract