# Clinch-Bonding Process for Ultra-High-Strength Steel and A5052 Aluminum Alloy Sheets

## TL;DR

This paper studies the clinch-bonding process for joining ultra-high-strength steel and aluminum alloy sheets, focusing on how different parameters affect the quality and strength of the joint.

## Contribution

The paper introduces a novel method using an adhesive with fine particles to control material flow and improve joint quality.

## Key findings

- Sheet combination significantly affects the cross-sectional shape and shear load of clinch-bonded joints.
- Die shape, punch velocity, and sheet holding force have narrow optimal ranges for defect-free joining.
- Using an adhesive with fine particles successfully improved the joining of 980 MPa steel and aluminum alloy sheets.

## Abstract

Initially, the effects of sheet combinations for joining two sheets, including 780 MPa steel and A5052 aluminum alloy sheets, on the joined cross-sectional shapes of the sheets in a clinch-bonding process and the tension-shear load of joined sheets were investigated. The effect of an adhesive on the amounts of the interlock and the minimum thickness in the upper sheet was not large, whereas the effect of the sheet combination was observed. Subsequently, for joining the upper 980 MPa ultra-high-strength steel and lower aluminum alloy sheets in the clinch-bonding process, the effects of the die shape, punch velocity, and sheet holding force on the joinability were investigated. As a result, defect-free conditions were narrowly constrained. Finally, a method that involved controlling material flow using an adhesive with fine particles to increase friction between the sheets was introduced. The upper 980 MPa steel and lower aluminum alloy sheets were successfully joined using this approach.