Effect of heat treatment on the flow induced corrosion of aluminum-silicon carbide(P) composites at elevated temperatures
[Thesis]
A. A. Khokhar
King Fahd University of Petroleum and Minerals (Saudi Arabia)
1995
130
M.S.
King Fahd University of Petroleum and Minerals (Saudi Arabia)
1995
Experimental studies such as electrochemical polarization measurements, weight loss, open circuit potential and elevated temperature closed loop techniques were used to investigate the effect of heat treatment on the corrosion resistance of aluminum metal matrix composite Al6013-20SiC(P) in 3.5 wt% NaCl solution and Arabian Gulf water, at temperatures ranging from 30C to 130C under controlled variable velocities. It was shown that alloy Al6013-20SiC(P) in T4-temper (age hardened) showed maximum resistance to corrosion. Studies on the variation of open circuit-potential of alloy Al6013-20SiC(P) in T4-temper with time, showed that the potential of the alloy shifted to more noble values compared to alloy in O-temper and F-form. A strong tendency for an oxide film formation on alloy in T4-temper was therefore suggested. Pitting was the most predominant form of localized corrosion attack, observed on the alloy. It occurred at metal matrix/SiC interface, and there was no evidence of attack on SiC particles. The pitting resistance of the alloy in general decreased on increasing the temperature from 30C to 130C. The alloy in T4-temper also showed a maximum resistance to pitting at elevated temperatures, compared to O-temper and F-form.