Electrochemical Studies of A16061-Cu-Sic Metal Matrix Composites in Sodium Hydroxide Solution by Weight Loss Corrosion Method

摘要

Metal matrix composites are heterogeneous systems containing matrix and reinforcement. Their physical and mechanical properties can be tailored according to requirement. They are used in automobile, aircraft and marine industries because of their increased corrosion resistance In this paper studies on the corrosion of Al6061-Cu-SiC metal matrix composites have been conducted. A16061 which is Commercial grade Al 6061 was alloyed with 1% copper and reinforced with silicon carbide particulates by the melt stir technique using vortex method. Composites containing 2, 4 and 6 percent of SiC were cast according to ASTM standards. Matrix alloy was also cast in the same way for camparision. Specimens of 20mm dia, 20 mm height were machined from the cast ingots. Corrosion studies were carried out by weight loss method in 0.25, 0.5 and 1M NaOH solutions as per ASTM G69-80. Specimens were dipped in the corrodent and removed at every 24 h intervals and weighed. The corrosion rate calculated using the formula 534W/DAT, decreased with increase in the exposure time for all specimens in all three concentrations of NaOH and decreased with the increase in reinforcement content of the composites.