Z. Huq, D. Larson, B. Mitton, University of North Dakota, Grand Forks, ND; J. Rindt, Alion Science & technology, Grand Forks, ND
Laser surface melting (LSM) has attracted growing interest in recent years for its ability to improve the corrosion performance of aluminum alloys. LSM is a versatile and promising technique that can be used to modify the surface properties of a material without affecting its bulk properties. The rapid heating and cooling cycles in LSM have been reported to dissolve the intermetallic particles within the melted layer, homogenizing the chemical composition of the layer. The corrosion of high strength aluminum alloys is dominated by the presence of micro-sized intermetallic particles. Dissolution of these particles and formation of a solid solution should therefore substantially improve the corrosion resistance of the surfaces. The aim of this study is to investigate the effect of high power fiber LSM using various shielding gases on the corrosion performance of friction stir welded (FSW) high strength aerospace aluminum alloys. The results will be compared with non-welded base materials. Surface morphology, microstructures, phase transformation and compositional changes will be reported. Corrosion data based on potentiodynamic polarization, open circuit potential, and electrochemical impedance tests performed on LSM surfaces immersed in a 0.5 M NaCl solution will be presented following this investigation.
Summary: Effect of Laser surface melting on corrosion performance of aerospace aluminum alloys
