چكيده به لاتين
The purpose of this study was to create an aluminum 6061 to St52 steel dissimilar joint and to investigate the effect of the transverse speed of the tool and the position of the pin relative to the bonding joint by the friction stir welding process. Due to the fact that aluminum to steel welding is very difficult by fusion methods due to the formation of fractured intermetallic compounds, hence using friction welding, it is tried to find optimal parameters by choosing and selecting optimal microstructure and mechanical properties. this research was carried out in six transverse speed modes of 16, 25, 40, 55, 70 and 85 mm / min (with a constant pin position of 0.2 mm), and three positions of pin of 0.2 mm, 1 mm and 0 mm (with a constant transverse speed of 70 mm / min) in the deviation toward the steel. In six transverse speed modes, the highest ultimate tensile strength at 85 mm / min to 200 Mpa, and in three positions of pin, the highest ultimate tensile strength in the position of 0.2 mm deviation toward the steel to 175 Mpa was obtained. According to the results of the Energy Dispersive X-ray Spectroscopy, an intermetallic layer formed in the joint is intermetallic compounds. in tensile specimens, fracture occurred mostly in the joints and the aluminum stir zone, due to the combination of thick intermetallic layer and steel fragments, respectively. In the weld area, different hardness values were measured due to different microstructures (SZ, TMAZ, HAZ). Using the micro hardness test, the hardness 75 HV in the aluminum mixing region and 315 HV the steel side close to the joint region is much higher than the base metals (Aluminum base metal is an average of 53 HV and an average metal base metal of 245 HV.
