Microstructure of friction stir welded dissimilar wrought 2017a and cast alsi9mg aluminum alloys

Abstract

Friction stir welding was applied to join dissimilar aluminum alloys: wrought 2017A and cast AlSi9Mg. The produced weldment was free from cracks and any discontinuities. The weld microstructure was composed of alternating bands of the welded alloys; however, the alloy that was placed on the advancing side (AlSi9Mg) dominated the weld center. The grain size within the particular bands was similar in both alloys. The hardness profile reflected the microstructure formed during welding. The weld microstructure as well as the shape of hardness profile across the weld were justified by numerical simulation of material flow during welding.