No abstract

The main objective of the current work was to produce sound Refill FSSW joints between AA6181-T4 aluminum and DP600 steel plates. The steel plates were used in two different surface conditions: with and without galvanized surface layer. The Taguchi statistical method was used to find out the set of parameters indicated to produce joint with higher mechanical resistance. Then, the possibility of joining these dissimilar metals using the Refill FSSW process was verified. Tool rotation speed and welding time were varied to observe its effect over the joint behavior. The results of lap shear tests showed that galvanized layers do not cause any substantial change on the final joint mechanical resistance, even though different joining mechanisms had been observed.

The use of welding of dissimilar materials in the manufacture of different products, both in automobile and civil construction industry, is necessary and understanding the factors that may interfere in the quality of the final product is important for its correct development. So, the main aim of this work was to perform the capacitive welding of different steels, evaluating the effect of different energies on the microstructural evolution and hardness profiles of the welded region. Three different steels were used as base materials (SAE 1045 carbon steel, DOMEX 700MC steel, and DOCOL DP 1000 steel), which were attached to a SAE 10B22 steel pin. To weld, the steels, a bank of capacitors was used, which allows different energies. The characterization of the materials was carried out through hardness verification and metallographic characterization tests. The results show that the capacitive discharge welding process generates a heataffected zone (HAZ) of short extension, regardless of the type of steel and the average welding energy. For the three types of steel that were used and for the different average welding energies, the microstructure formed in the HAZ was martensite.