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Guzman, D., Garcia, C., Soliz, A., Sepulveda, R., Aguilar, C., Rojas, P., et al. (2018). Synthesis and Electrochemical Properties of Ti-Si Alloys Prepared by Mechanical Alloying and Heat Treatment. Metals, 8(6), 417.
Abstract: The aim of this work was to study the synthesis and electrochemical properties of Ti 2 wt %-Si alloys prepared by mechanical alloying (MA) and heat treatment. The MA process was performed under Ar atmosphere. The structural, morphological, and compositional evolutions during the milling and subsequent heat treatment were investigated by X-ray diffraction, energy-dispersive spectroscopy, and scanning electron microscopy. The electrochemical behavior was evaluated by open circuit potential and linear sweep voltammetry measurements. The results showed that the MA process promotes the formation of a supersaturated alpha-Ti-Si solid solution. During heat treatment, the Si remaining in the mechanically alloyed powders and the Si from the alpha-Ti-Si supersaturated solid solution reacted with Ti to form Ti-Si intermetallic compounds. These compounds have a fine and homogeneous distribution in the alpha-Ti matrix, which cannot be achieved by conventional casting methods. Additionally, the electrochemical evaluations revealed that the mechanically alloyed and heat-treated Ti 2 wt %-Si powders have better corrosion resistance in 1.63 M H2SO4 than the pure Ti and MA Ti-Si samples. This is likely due to the particular microstructure produced during the milling and subsequent heat treatment.
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Vasco, D. A., Munoz-Mejias, M., Pino-Sepulveda, R., Ortega-Aguilera, R., & Garcia-Herrera, C. (2017). Thermal simulation of a social dwelling in Chile: Effect of the thermal zone and the temperature-dependant thermophysical properties of light envelope materials. Appl. Therm. Eng., 112, 771–783.
Abstract: As in most countries, Chile exhibits a continuous growth of energy demand, although nowadays the country does not have enough conventional energy sources to supply it. For this reason, energy saving approaches in the residential sector have been encouraged. One of the solutions to improve the energy performance of the buildings is to decrease wasting energy through the building's envelope, therefore the thermal properties of materials used in building envelopes must be analyzed to evaluate the thermal response of houses. Normally, the thermal envelope of a social house in Chile is made of brick or wood along with light materials such as fiber cement, plasterboard, and thermal insulating materials as polystyrene foam. The experimental part of this work deals with the measurement of the thermal conductivity and thermal diffusivity of the aforementioned light materials in a temperature range from -5 degrees C to 40 degrees C through the transient line heat source method. The experimental results allowed the identification of 10-20% variation of those thermophysical properties. The response of the thermal envelope and the inner temperature of a social dwelling under seven different climatological conditions was evaluated through transient simulations with EnergyPlus. The results allowed to identify that the dwellings located in hotter zones are prone to having higher temperatures than the comfort temperature, and the recommendations of the thermal regulations in Chile are more effective in the colder thermal zones 6 and 7. (C) 2016 Elsevier Ltd. All rights reserved.
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