Effect of Temperature and Zinc Coating on Interfacial Bonding between Steel and Aluminum Dissimilar Material

摘要

The application of aluminum alloys can largely reduce the weight of the vehicle body and save energy. In order of the wide use of aluminum alloy the study on the joining method of steel and aluminum dissimilar materials is very important. In order to expose the mechanism of the interface bonding between steel and aluminum dissimilar materials under the thermal and mechanical coupled loading, steel sheets were joined to 6061 aluminum sheets by a thermal and mechanical simulation system. The applied temperature and pressure were both able to be controlled precisely in the Gleeble simulation testing system. The effects of welding temperature and zinc coating on interfacial bonding were both studied. It was shown that without zinc coating a continuous interface layer between the steel and aluminum could be observed when the temperature was above 550°C. There was a FeAl3phase existing in the interface layer with a high micro hardness. When welding temperature higher than 550°C the shear strength of the joint increased with temperature. With zinc coating a continuous interface layer could be formed above 470°C. The interface layer was mainly composed of Fe2Al5Znxand Al-Zn eutectic phases instead of the FeAl3.