PNNL

Abstract

Friction stir welded (FSW) aluminum-magnesium lightweight vehicle joints have gained significant interest due to their high strength-to-weight ratio. In this work, the corrosion resistance of this material is analyzed through electrochemical tests, which include open circuit potential (OCP), and potentiodynamic polarization scans (PD). Corrosion rate of the FSW weld is being tested by weight loss measurement through cyclic corrosion test (CCT) according to SAEJ 2334 standard. Mechanical properties, including lap-shear strength, hardness mapping, and true stress-strain curves are also investigated. The electrochemical results indicate that the corrosion property of the center weld zone stays in between of the two base alloys. Indentation tests show the weld zone behaves differently from base alloys. Lap shear strength surprisingly did not drop too much even after eight weeks of cyclic corrosion test.