The paper describes the mechanical properties and the corrosion behaviour of three Al-Si alloys in 0.5 M NaCl solution. The alloys have exhibited similar values of hardness, but the highest tensile strength and the lowest elongation have shown the specimens of alloy with 11.38 % of silicon. Higher content of both copper and magnesium has contributed to better tensile strength and lower elongation of as-cast hypoeutectic alloys. The harmful effects of iron on mechanical properties of all alloys have been reduced to some extent by nickel and cobalt addition. The differences in the values of the open circuit potential of the examined alloys were insignificant. The thickness of the protective oxide layer has increased over time, and the layer has become very compact. Slight differences in the values of the corrosion potential of the alloys were determined, whereas the lowest value of the corrosion current was indicated for the hypereutectic alloy. The presence of intermetallic phases in the alloys has shown that the oxide film was not consistent. The severe pits have not been found at the surface of the corroded samples. Based on the obtained results, the examined alloys may be used for the manufacturing of the internal combustion engine parts.

This paper describes the mechanical and corrosion properties of an Al-Fe-Si aluminum alloy containing 0.89 wt. percentage of Fe and 0.15 wt. percentage of Si. These properties are compared to those of aluminum sheets of commercial purity. AA 8079 sheets/foils show higher strength and similar plasticity as A199.7 sheets/foils. Recrystallization response curves of AA 8079 and A199.7 hardened foils show no significant difference between these materials in the sense of the temperatures of beginning and the end of the primary recrystallization. Minimizing of earring for as/rolled and annealed products is made possible by appliance of high degrees of cold rolling deformation ratios in final stages of material processing. Corrosion rates and corrosion currents of AA8079 are higher for 16-20%, and values of polarization resistance are lower by about 14-17%, compared to the A199.7 in both fresh water and 0.51 mol NaCl.

Microstructural examinations of Al-Si alloys intended to manufacture IC engine components revealed a complex phase composition in all samples. Polyhedral crystals of primary silicon were detected in Al-12.5Si alloy, besides the ?-Al phase, eutectic silicon, and several intermetallic phases, identified in the cast samples of both alloys. Better tensile properties were found for samples of Al-11Si. Predominantly intercrystalline fracture with features of ductile failure was observed in both alloys. In as-cast specimens of Al-11Si alloy, the cracks were formed by the decohesion mechanism between the particles of the intermetallic phase AlCuFeNi and ?-Al phase. The microcracks initiated on the interface were spread along the branches of ?-Al15(Fe,Mn,Cu)3Si2 particles. After T6 treatment of Al-11Si alloy, almost half the intermetallics quantity presented Al3Ni phase, while the iron-based phases were observed in a small amount. Spheroidized eutectic silicon, less portion of Al5Cu2Mg8Si6, and a more considerable quantity of Al3(Fe,Mn,Cu,Ni,Co) were detected for T6 specimens of Al-12.5Si alloy. The rounded crystals of eutectic silicon contributed to the improvement of their tensile properties. Larger and deeper dimples of mostly polygonal shapes were observed in the samples of Al-11Si alloy after T6 treatment. The microcracks have occurred at the boundary of the intermetallic phase/?-Al solid solution.

Article Highlights • Broken honeycomb-like perlite structure as catalyst support • Morphological, textural, and structural characteristics of Ni and Mg influence • Correlation between reducibility and hydrogen chemisorption • Evaluation of lowest reduction temperature for catalyst preparation • Catalyst behavior due to Ni and Mg influence in hydrogenation process Abstract Use of broken honeycomb-like expanded perlite as support for magnesium modified nickel catalysts in process of partial hydrogenation of sunflower oil was studied. By the use of the precipitation-deposition method, two groups of precursors were synthesized: different Ni/SiO 2 mole ratios with constant Mg/Ni mole ratio 0.1, and different Mg/Ni mole ratios with constant Ni/SiO 2 mole ratio 0.25. Characterizations of precursors were done (scanning electron microscopy, diffuse reflectance UV-Vis, infrared spectroscopy, N 2-physisorption, temperature programmed reduction (TPR) and He-pycnometry) to determine the material differences, considering the change in morphology, structure, texture and reducibility with overall Ni and Mg content. In addition, TPR and hydrogen chemisorption were performed in order to estimate the temperature reduction range of supported precursors and the dispersion degree of nickel in reduced precursors, respectively. The interaction between Ni 2+ and perlite support was established. Different reducibility and dispersion were obtained as a function of Ni/SiO 2 and Mg/Ni mole ratios. After the precursor's reduction and paraffin oil impregnation, the obtained catalysts were tested in a sunflower oil hydrogenation reaction. Catalyst activity was monitored through the decrease of the refractive index and hydrogen consumption that gave the insight that the influence on catalyst activity represents the accessibility of triacylglycerols and not always the hydrogen determined dispersion degree.

This paper describes the general trends correlating mechanical and corrosion properties with chemical composition of some Al-Fe-Si and Al-Fe-Mn-Si alloys for foils. These Al-rich eutectic alloys based on Al-Fe-Si and Al-Fe-Mn, when roll cast and appropriately processed to give fine and regular dispersion of intemetallic particles, can provide good combinations of strength and ductility. These characteristics have been responsible for the alloy success in replacing commercially pure (CP) aluminum for applications in thin sheet and foil gauges. The objective was to obtain an opinion about the possible role of alloying elements in corrosion behavior and mechanical properties of these commercial materials produced by cold rolling of twin roll cast strips.