Self-piercing rivetability of steel/aluminum and its improvement using reinforcing plate

Abstract

Producing high-quality joints between high-strength steel and aluminum alloy presents a challenge, yet it is crucial for manufacturing state-of-the-art lightweight. This study investigates self-piercing riveting (SPR) for joining high-strength steel to aluminum alloy panels. The experimental results for both steel-on-top (SOT) and steel-on-bottom (SOB) configurations are presented for a range of ultimate tensile strength (UTS) values of steel up to 1180 MPa. The findings show that the SOT configuration consistently produces high-quality joints, whereas the SOB configuration, especially with higher UTS steel panels, results in inadequate joints. To overcome the challenge of the SOB configuration, we propose a novel approach that uses reinforcing aluminum plates beneath the lap joints during the SPR process. The cross-sectional characteristics and mechanical performance of joints formed with varying thicknesses of reinforcing plates under both configurations are discussed. The results demonstrate that introducing the reinforcing plates in the SOB configuration effectively eliminates geometrical defects and ensures acceptable joint strength, even with high-strength steel. © 2024