A Study the Friction Stir Welding between of 6063 and 7075 Aluminum Alloy Tailored Blank

Abstract

The tailored blank joint and welding dissimilar materials are the most effective way that can be used to reduce a total automobile weight and the fuel consumption of the vehicle. However, a fusion welding of this joint is difficult due to the differences of material properties such as a melting temperature, a heat conductivity, etc. Therefore, a welding process that could produce a successful joint of these materials is continuously developed and optimized. This research aims to study the influence of welding parameters of the friction stir welding (FSW) process for producing the tailored blank joint between a 6063 and a 7075 aluminum alloy. The experiments were carried out by using sample sizes of a 150 mm. long, 75 mm. wide and different thickness of 3.0 mm and 6.0 mm. for the 6063 aluminum alloy and the 7075 aluminum alloy respectively. The samples of the two different materials were mouthed into the fixture and welded by using FSW process. The welding parameters including rotating speed, welding speed and tilt angle were varied from 250 -750 rpm, 25-125 mm/min and 0-4 degree respectively. The welded samples were tested and compared the tensile strength, micro-hardness and micro-structure of the joint. The experimental results showed that the rotating speed, welding speed and tilt angle influenced the tensile strength and micro-structure of the joint. However, they did not influence the hardness of the joint. The result also indicated that the most suitable parameters for FSW of the 6063 and the 7075 aluminum alloy materials by using the rotating speed of 750 rpm, the welding speed of 25 mm/min and the tool tilt angle of 0 degrees which gave the highest tensile strength of 181 MPa. This tensile strength was almost the same as the original material properties.