Influence of Surface Damage on Weld Quality and Joint Strength of Collision-Welded Aluminium Joints

TL;DR

This paper investigates how surface scratches affect the quality and strength of collision-welded aluminum joints.

Contribution

The study provides new insights into the impact of surface imperfections on collision welding outcomes using specific aluminum alloys.

Findings

Collision velocity and angle significantly influence the weld quality of AA6110A-T6 and AA6060-T6.

Surface scratches reduce tensile shear strength and alter jet formation during collision welding.

SEM and high-speed imaging reveal how surface damage affects bonding interface integrity.

Abstract

Collision welding represents a promising solid-state joining technique for combining both similar and dissimilar metals without the thermal degradation of mechanical properties typically associated with fusion-based methods. This makes it particularly attractive for lightweight structural applications. In the context of collision welding, it is typically assumed that ideally smooth and defect-free surface conditions exist prior to welding. However, this does not consistently reflect industrial realities, where surface imperfections such as scratches are often unavoidable. Despite this, the influence of such surface irregularities on weld integrity and quality has not been comprehensively investigated to date. In this study, collision welding is applied to the material combination of AA6110A-T6 and AA6060-T6. Initially, the process window for this material combination is determined by systematically varying the collision velocity and collision angle—the two primary process parameters—using a special model test rig. Subsequently, the effect of surface imperfections in the form of defined scratch geometries on the resulting weld quality is investigated. In addition to evaluating the welding ratio and tensile shear strength, weld quality is assessed through scanning electron microscopy (SEM) of the bonding interface and high-speed imaging of jet formation during the collision process.

Figures