Examining the influence of Scandium interlayer and parameters on the mechanical behaviour in FSW of AA 5754-H111 plate through response surface approach

Abstract

Friction stir welding (FSW) was conducted on 5754-H111 aluminium alloy using a response surface methodology to examine the impact of process parameters on the efficiency of the weld. The key FSW parameters were the percentage of scandium inclusion in the interlayer, tool rotational speed, and tool travel speed. The significant responses were identified as the tensile strength of the weld and the hardness in the weld zone. An Al-Mg-Sc alloy was employed as an interlayer material between the 5754 plates to enhance the strength in the weld zone. The addition of Scandium had a more pronounced effect on the hardness of the stir zone. The tensile strength was increased by raising the tool’s rotational speed. The results showed that the maximum tensile strength of the joints was 225 MPa and the hardness was highest at 118 HV1 in the weld stir zone. The introduction of Scandium improved the joint strength by producing fine grains and Al _3 Sc precipitates. The welding speed had the least impact on the tensile properties of the joint among all the variables investigated.

Keywords

• friction stir welding
• Scandium interlayer
• response surface method
• tensile strength
• hardness.