Research Interests:
Research Interests:
In this investigation the corrosion resistance of four Al-Si hypereutectic alloys in a solution typical of condensate from automotive fuel combustion products, and referred to here as synthetic condensed automotive solution, has been... more
In this investigation the corrosion resistance of four Al-Si hypereutectic alloys in a solution typical of condensate from automotive fuel combustion products, and referred to here as synthetic condensed automotive solution, has been studied. Three commercial alloys that are used for cylinder liners, and a laboratory made alloy, were studied by electrochemical impedance spectroscopy and measurements were taken after increasing times of immersion in this solution. Comparison of the electrochemical response of the four alloys in the corrosive solution was carried out. Although the mechanisms by which the four alloys corroded were similar, the results indicated differences in corrosion resistances of these alloys, and these differences could be related to their microstructures. The laboratory prepared alloy showed increased susceptibility to pitting corrosion compared to the commercial alloys. The surfaces of the alloys were examined, before and after the corrosion test, by scanning electron microscopy and analyzed by energy dispersive spectroscopy. The results indicated preferential attack of the aluminium matrix phase in all the alloys. The alloy with higher copper content and prepared by spray forming was more susceptible to pitting compared to the other alloys. The EIS response at low frequencies indicated a diffusion-controlled process, probably that of oxygen to the alloy interface.
Research Interests:
Research Interests:
Research Interests:
Research Interests: Engineering, Materials Engineering, Biomedical Engineering, Scanning Electron Microscopy, Metal matrix composite, and 23 moreCeramics, Lasers, Mice, Animals, Temperature, Zinc, T cells, Chip, X ray diffraction, Electrical Properties, Surface Properties, Microstructures, Powders, Cell Proliferation, Osteoblasts, Bone Substitutes, Materials Testing, Durapatite, Process Parameters, Breakdown Voltage, Biocompatible Materials, Silicon Dioxide, and Bone and Bones
In this investigation the corrosion resistance of four Al-Si hypereutectic alloys in a solution typical of condensate from automotive fuel combustion products, and referred to here as synthetic condensed automotive solution, has been... more
In this investigation the corrosion resistance of four Al-Si hypereutectic alloys in a solution typical of condensate from automotive fuel combustion products, and referred to here as synthetic condensed automotive solution, has been studied. Three commercial alloys that are used for cylinder ...
Research Interests:
The purpose of this work was to investigate the effect of carbon and nitrogen in 17%Cr ferritic stainless steels (16%Cr-0.04%C-0.032%N; 17.2%Cr-0.02%C-0.0062%N; 18.5%Cr-0.008%C-0.0213%N) on the degree of sensitization (DOS). These steels... more
The purpose of this work was to investigate the effect of carbon and nitrogen in 17%Cr ferritic stainless steels (16%Cr-0.04%C-0.032%N; 17.2%Cr-0.02%C-0.0062%N; 18.5%Cr-0.008%C-0.0213%N) on the degree of sensitization (DOS). These steels were solution annealed at 1200ºC and quenched in water. Isothermal treatments were carried out at 600ºC between 5 minutes and 16 hours. The Double Loop Electrochemical Potentiokinetic Reactivation test (DL-EPR) was carried out in a 0.5M H2SO4 solution at (25 ± 2)ºC. The DOS was evaluated using a ratio between maximum anodic current density in reversion, ir, and activation, ia. The microstructural examination of specimens was carried out using optical and scanning electron microscopy after metallographic etching with Vilella's reagent. The results showed a DOS variation with time. Maximum values of DOS were obtained for each steel, followed by its reduction. The intensity of DOS and its kinetics vary in function of the carbon and nitrogen content in steels.