Corrosion Properties of Advanced Materials like Aluminium 6013 Metal Matrix Composites Reinforced with Red Mud Particulates in Acid Chloride Medium

摘要

This paper deals with the corrosion characterization of red mud particulate aluminium 6013 alloy metal matrix composites for automobile application owing to their low cost and equivalent or superior performance. Presently, little research is done to study the environmental behaviour of these alloys. Aluminium 6013 alloys have a relative high strength compared with zinc alloys with a low melting point. Hence it was used as the matrix alloy in the present research. Red mud being a ceramic remains inert and is hardly affected by the acidic medium. Red mud particles of size 50-80 u are used as reinforcement. Experiments were conducted to determine the corrosion rate of the samples in acid chloride medium by static weight loss method. Metal matrix composites are prepared according to ASTM standards by liquid melt metallurgy technique using vortex method. Composites containing 2,4 and 6 % by weight of red mud and unreinforced matrix were tested using different concentrations of hydrochloric acid at room temperature. Specimens are taken in the form of 20 mm x 20 mm cylinders. Specimens are subjected to scanning electron microscopy to get the microstructures. Corrosion rates of all samples were calculated using the formula 534 W/DAT mpy. The results were computerized and simulation curves were obtained. The composite was found to be more corrosive resistant than matrix alloy. In each test the corrosion resistance of both alloy composites was found to decrease with the exposure time. The decrease in the corrosion rates of composites when compared to that of matrix alloy is due to the physical barrier created by red mud particles.