In‐service sensitization of a microstructurally heterogeneous AA5083 alloy

Abstract

It was revealed that an AA5083 alloy had been severely sensitized after 40 years in service at ground atmosphere temperature.The degree of sensitization of the various regions through the alloy plate thickness is different, which is associated with the non-uniform distribution of Mg through the plate thickness. The alloy plate exhibits Mg-rich bands that promoted the heterogeneous distribution of Mg-containing precipitates. The composition of these precipitates ranges from that for low Mg content intermetallics to that of the b 0 phase. Structure characterization revealed the b 0 phase and a cubic Al-Mg phase that has lower magnesium contents compared to the b phase.

Optimization of process parameters for friction stir welding of dissimilar aluminum alloys using different Taguchi arrays

“…Therefore, the shiny particle is attributed to the α-AlFeMnSi intermetallic. This is consistent with the result noted by Wei et al [63]. The S2 particle (Fig.…”

Mechanical properties, corrosion behavior, and microstructure of Sr modified Al–9.2Mg–0.7Mn alloys

“…However, when Mg is present in levels greater than 3.5 wt%, Al–Mg alloys are susceptible to intergranular corrosion (IGC) and stress corrosion cracking (SCC) when exposed to elevated service temperatures (above 65°C) . Especially for high Mg content alloys, during sensitization treatment, the supersaturated Mg atoms are precipitated at the grain boundaries in the form of β‐phase (Al 3 Mg 2 , which is anodic relative to the Al matrix) and are continuously distributed, thereby making Al–Mg alloys are prone to IGC and SCC …”

A Critical Review of Anti-Corrosion Chemical Surface Treatment of Aluminum Alloys Used for Sports Equipment

“…Schematic diagram of the self-healing process of aluminum oxide at room temperature [7] With consideration of magnesium alloying elements in high-strength aluminum alloys, intergranular corrosion is prone to occur in corrosive environments. As shown in Figure 4, Wei et al [26] employed a scanning electron microscope and SEM ultamicrotome (GATAN 3View) to reveal the magnesium-rich precipitates resulting in the severe sensitization of AA 5083 alloy in a marine environment. With consideration of magnesium alloying elements in high-strength aluminum alloys, intergranular corrosion is prone to occur in corrosive environments.…”

“…With consideration of magnesium alloying elements in high-strength aluminum alloys, intergranular corrosion is prone to occur in corrosive environments. As shown in Figure 4, Wei et al [26] employed a scanning electron microscope and SEM ultamicrotome (GATAN 3View) to reveal the magnesium-rich precipitates resulting in the severe sensitization of AA 5083 alloy in a marine environment. In addition, Zhang et al [27] employed electrochemical measurement and a scanning electron microscope to reveal the transition from intergranular corrosion to crystallographic pitting in AA 2024-T351 aluminum alloys in 3.5 wt.% NaCl solutions as shown in Figures 5 and 6.…”