An Investigation of the Friction Stir Scribe Welding for Lap Joint of Dissimilar Materials AA6022-AZ31B

Abstract

Friction stir welding (FSW) has emerged as a versatile solid-state joining technique for metals. However, joining dissimilar materials with significantly different melting points and material properties remains a challenge. Friction stir scribe (FSS) welding, a variant of FSW, offers a promising solution for lap joints of such materials. This technique modifies a conventional FSW tool by incorporating a small offset scribe at the tip of the welding pin. This research investigates the feasibility of FSS welding for lap joints between AA6022 aluminum alloy and AZ31B magnesium alloy. The focus of this study is to understand the influence of scribe and Different Lap configuration on the microstructure and mechanical properties of the lap joint.  The investigation will involve FSS welding of AA6022 and AZ31B plates under various configurations, with the scribe and the plates arranged in different position (AA6022 on top or AZ31B on top). Microstructural characterization will be conducted to examine the formation of the material phases within the weld zone. Additionally, fracture load testing will be performed to evaluate the joint strength and identify the failure modes.

This research aims to contribute to the development of FSS welding for dissimilar material joining. By analyzing the impact of scribe and plate arrangement on the microstructure and mechanical behavior, valuable insights can be gained for optimizing the FSS process to create high-integrity lap joints of AA6022-AZ31B and potentially other dissimilar material combinations.