Corrosion behaviour of aluminium metal matrix composites reinforced with TiC processed by pressureless melt infiltration

Abstract

The corrosion resistance of commercial aluminium alloy (2024) and binary Al-Cu x and Al-Mg x alloys reinforced with TiC particles using a pressureless infiltration method has been evaluated in 3.5% NaCl solution using potentiodynamic polarization curves and linear polarization resistance measurements. The TiC preforms were sintered at 1250, 1350 and 1450°C and infiltrated in the range of 900-1200°C under argon atmosphere. Some specimens were heat treated at 530°C for 150 min, water quenched and subsequently artificially aged at 190°C for 12 h in an argon atmosphere and naturally aged at room temperature for 96 h, respectively. The corrosion resistance of the composites was evaluated as a function of the addition of Cu and Mg into the aluminium. In all cases pitting corrosion was observed with or without additions of Cu or Mg, but these elements increased the anodic corrosion current. However, it was found that addition of TiC particles in the composite without heat treatment reduced the anodic current density and the number and size of pits in the Al-2024 alloy. When the heat treatment was applied to the composite, either artificially or naturally aged, the anodic current density of the Al-2024 alloy increased.

Effect of Magnesium Content on the Corrosion Behaviors of Grf/Al Composite

“…With the increase of magnesium content, the E corr of the Gr f /Al composite decreased sharply because the E corr of magnesium (-1.84 V, saturated calomel electrode, SCE) is lower than that of Al (-0.83.V SCE). This result is consistent with Albiter et al's [8] investigation on TiC p /Al composites of different magnesium contents. It should be noted that the i corr of Gr f /Al-3.2Mg was the lowest, which indicated that Gr f /Al-3.2Mg has the best corrosion resistance among the four composites.…”

Effect of fly ash reinforcement on the corrosion behaviour of cast Al-Mg alloy A535 in 3.5 wt% NaC1 solution

“…It can be seen that A535 alloy has superior pitting corrosion resistance to the composites. The corrosion behaviour of particulate Al MMCs is influenced by several factors such as porosity, high dislocation densities at the matrix-reinforcement interfaces, the presence of intermetallic compounds (IMCs) and reaction products, and the electrical conductivity of the reinforcing phases [19]. Gikunoo and Oguocha [24] have reported that the amount of dimagnesium silicide, Mg 2 Plot of E p -E corr for A535 alloy and its MMCs in 3.5wt% NaCl solution (pH = 7).…”

“…The corrosion behaviour of Al-based MMCs reinforced with particles such as Al 2 O 3 , garnet, TiC, AlN and SiC particles have been studied by several workers [12][13][14][15][16][17][18][19][20][21]. A close look at the results obtained from these studies shows that three types of corrosion can occur in particulate Al MMCs at room temperature.…”

Microstructure, Wear, and Corrosion Characteristics of TiC-Laser Surface Cladding on Low-Carbon Steel

“…Generally, many works reported that the corrosion resistance of composites was higher than that for their alloys. [34][35][36] …”