Corrosion Current Distributions of Pure Titanium/Type 5083 Aluminum Alloy Friction Welding Joints in 3.5%NaCl Solution

Abstract

Corrosion current distributions of the friction welding joints between commercially pure titanium (Ti) and type 5083 aluminum alloy (A 5083) were measured in a 3.5% NaCl solution by using the scanning vibrating electrode technique. A 200nm-thick intermetallic compound layer was formed at the welded interface at the friction time of 3.0s. This intermetallic compound layer reduces the tensile strength of the friction welding joint. It is suggested that the intermetallic compound layer were comprised of τ-Al (Ti₂Mg₃Al₁₈), Mg₂Al₃, and Al₃Ti phases. The friction welding joint with the intermetallic compound layer at the welded interface was less susceptible to galvanic corrosion, whereas pitting corrosion occurred in the friction welding joint having only the Mg concentrated area at the welded interface. Therefore, it is considered that the intermetallic compound layer can suppress the galvanic corrosion.