Resumo Congresso

Abstract

The application of light metals such as aluminum (Al) and titanium (Ti) in the transportation industry is very important, as they have a high mechanical resistance with a low weight, which produces more environmentally friendly structures. However, as the cost of producing Ti is higher, the industry has joined Al and Ti in order to produce the multi-material structures with an intermediate cost and a superior mechanical and corrosion properties. In despite of this, the joining materials with such distinct physical and chemical properties is still a challenge for the industry. Currently, spot welding processes of dissimilar materials either increase the weight of the structure, such as riveting, or have a high energy consumption, such as resistance spot welding or laser welding. An alternative spot welding of dissimilar materials is the process developed by HGZ, called Friction Spot Welding (FSpW), which has obtained satisfactory results in the welding of overlapping joints of Al-Al, Al-Mg, Mg-Mg, Al-Steel. The literature presents that 6181-T4 and Ti-6Al-4V overlap joints were successfully produced through this welding process. However, the microstructural changes occurring on the aluminum surface and its influence on the corrosion resistance in the different welding zones were not evaluated. These changes may modify the passive film in these regions, which could result in a difference in the corrosion resistance and reduce the lifetime of the welded joint. In this way, the objective of this work is to evaluate the influence of the welding process by Friction Spot Welding on the corrosion resistance of the aluminum surface in the dissimilar joint AA6181-T4/Ti-6Al-4V through analysis of optical microscopy (MO), microscopy Scanning electron microscopy (SEM), impedance analyzes. The results indicated that the thermal cycle effect generated by the FSpW welding process affects corrosion resistance of aluminum surface of the welded joint AA6181-T4/Ti-6Al-4V.

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