Influence of Joining Method on Electrochemical Corrosion Properties of 7020 Aluminum Alloy Joints
The results of corrosion properties research of aluminum alloy AW 7020 (AlZn5Mg1) welded by friction stir welding (FSW) and MIG were presented. Friction Stir Welding (FSW) – a new technology can be successfully used for butt welding of different types of aluminum alloy sheets. In the paper, the parameters for friction stir welding of sheets made of AlZn5Mg1  alloy were presented as well as parameters for MIG. Metallographic analysis of bonds showed a proper structural construction of both, the FSW and MIG welded 7020 aluminum alloys.The study was carried out in accordance with the requirements of the ASTM G 106. EIS measurement was performed in three-electrode system in artificial seawater (3.5% NaCl). Impedance studies were carried out at the corrosion potential. Changed voltage signal amplitude in the range ±10 mV and frequency range of changes was as follows: 100 kHz – 0.1 Hz. Atlas 0531 EU & IA potentiostat was used for studies.The results of electrochemical impedance spectroscopy are presented in the form of parameters characterizing the corrosion process. Obtained results were statistically analyzed.The electrochemical impedance spectroscopy studies have shown that the joint welded by FSW has better electrochemical corrosion resistance than the joint welded by MIG and the native material – AW-7020 alloy.Original value are received results of the corrosion properties of new method friction stir welded AlZn5Mg1 alloy compared with traditional MIG method and the native material.
Algirdas V. Valiulis, Olegas Černašėjus and Vadim Mokšin
K. Dudzik, "Influence of Joining Method on Electrochemical Corrosion Properties of 7020 Aluminum Alloy Joints", Solid State Phenomena, Vols. 220-221, pp. 589-594, 2015