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Nano aluminum oxide was prepared by the combustion method using aluminum nitrate as the oxidizer and urea as a fuel. Characterization of synthesized materials was performed using SEM (scanning electron microscope), powder XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), and TEM (transmission electron microscope). Al-Mg/Al2O3 (2, 4, 6, and 8 wt%) metal matrix nanocomposites were prepared by liquid metallurgy route-vertex technique. The homogeneous dispersion of nano Al2O3 particles in Al-Mg/Al2O3 metal matrix nanocomposites (MMNCs) was revealed from the field emission SEM analysis. The reinforcement particles present in the matrix were analyzed through energy-dispersive X-ray spectroscopy method. The properties (corrosion and mechanical) of the fabricated composites were evaluated. The mechanical and corrosion properties of the prepared nanocomposites initially increased and then decreased with the addition of nano Al2O3 particles in Al-Mg Matrix. The studies show that, the presence of 6 wt% of nano Al2O3 particles in the matrix improved the properties of other combinations of nano Al2O3 in the Al-Mg matrix material. Further, the Al-Mg/Al2O3 (6 wt%) MMNCs are joined by friction stir welding and evaluated for microstructural, mechanical, and corrosion properties. Al-Mg/Al2O3 MMNCs may find applications in the marine field. The response surface method (RSM) was used for the optimization of tensile strength, Young’s modulus, and microhardness of the synthesized material which resulted in a 95% of statistical confidence level. Artificial neural network (ANN) analysis was also carried out which perfectly predicted these two properties. The ANN model is optimized to obtain 99.9% accurate predictions by changing the number of neurons in the hidden layer.

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We report on the fabrication and electrical characterization of aligned multiwall nanotubes (MWNTs) grown on a four-probe patterned catalyst layer. This structure has been designed to directly measure the electrical property of as-grown MWNTs. The temperature-resistance results show that the aligned MWNTs are semiconducting in directions perpendicular to the tube axis and follow the three-dimentional hopping conduction mechanism. Effects of oxygen plasma on the characteristics of the MWNTs are also investigated. Raman spectroscopy results indicate that oxygen plasma treatments can be used to reduce the carbonaceous material in the film. As the exposure time of oxygen plasma increases, the resistance of the aligned MWNTs increases mainly due to the suppression of current conduction through carbonaceous materials. These results suggest that oxygen plasma treatment is effective in improving the film quality of as-grown MWNTs.

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