Optimización de la resistencia a la corrosión de un bronce al aluminio en un ambiente corrosivo controlado.

Abstract

The aim of this research was to optimize the corrosion resistance of a bronze to aluminum in a controlled corrosive environment, in order to determine an alloy of better anti-corrosive properties for these types of alloys. This project aims to be a starting point for future research in the area of corrosion. The research has studied the alloys CuAl4, 5; CuAl7, 1; CuAl10, 1 (ASTM B824). For this, it began with its manufacture of these alloys. At each casting, the chemical composition was evaluated by spectrometry (OES) and small test pieces were obtained from each of them. An attack with chemical reagents is performed to reveal its metallic phases. For this FeCL3, HCL in 95% Ethanol and FeCL3, HCL, CrO3 in distilled water are used. The microstructures obtained were characterized by metallography using two microscopes, one optic and one scanning electron (SEM), comparing the obtained phases, which will be different for each aluminum arrangement. Small test tubes were again taken from each alloy, electrochemical corrosion tests were carried out on each alloy. In corrosion, artificial seawater (ASTM D1141) was used as electrolyte at pH 10±0.3. The corrosion products were successively characterized by (EDS and SEM). Once the identification phase was over, the products were removed with chemical reagents. A 50% HCL solution is used for cleaning. The corrosive attack damage was then identified in each microstructural matrix. Corrosion rates were subsequently assessed for each combination. Finally, the data were optimized by means of the software (RStudio®, MATLAB and Minitab®), the equation CR= 7.928-0.282Al+4.7Sn was obtained; expressing that the higher increase in aluminum there is a lower corrosion rate for a maximum limit of Al= 10,11%; Sn=0.13%; CR=5,170 mpy, also demonstrates that these alloys are effective for marine environments with high salinity. The use of this equation is recommended to avoid unnecessary corrosion testing considering the pH parameters cited in this research project. In terms of the optimization methodology it is recommended to use them for any type of ferrous or non-ferrous alloy whose variables are dependent on their chemical composition.