Friction Press Joining of Laser-Texturized Aluminum with Fiber Reinforced Thermoplastics

Abstract

Friction Press Joining (FPJ) is a suitable method for producing composites of aluminum and thermoplastics in lap joint configuration, which is based on modified Friction Stir Welding (FSW). During the joining process, a rotating cylindrical tool is pressed onto an aluminum surface. The resulting friction generates heat that is conducted to the bonding zone, leading to localized softening of the thermoplastics. In combination with the tool’s axial force and a suitable pre-treatment of the aluminum surface, a resilient composite compound is created. This paper presents the results of a surface pre-treatment of aluminum using laserradiation. The textures are essential for a strong connection, as they can significantly influence effective joining mechanisms, such as microscopic and macroscopic form fit. The experiments were carried out using different surface treatments by means of a single-mode laser for joints of aluminum (EN AW-6082 T6) and glass fiber reinforced polyamide (PA6 GF15). The aim of the study was an increased understanding of process behavior and joining mechanisms. The shear strength could be increased by 40 % compared to previous studies with the presented laser surface treatment.

A Holistic, Model-Predictive Process Control for Friction Stir Welding Processes Including a 1D FDM Multi-Layer Temperature Distribution Model

“…The thickness of the sheet material was 5 mm. The aluminum alloy EN AW-6082-T6 (Gemmel Metalle & Co. GmbH, Berlin, Germany) [33] with a thickness of 3 mm, is a standard alloy used in many applications with plastic-metal direct bonds [10,34].…”

“…The surface pretreatment has a considerable impact on the subsequent mechanical strength of the bond and the occurring adhesion mechanisms in the joint. Mechanical processes, such as grinding [6], sandblasting [7], or pre-drilling [8], as well as chemical [9] and optical [5,[10][11][12] methods were studied as methods for the pretreatment. In this context, laser-based methods demonstrated both economic and technological advantages [5,12].…”

“…Alongside the experiments concerning the surface pretreatment, Wirth et al [10] also analyzed the joining process itself. The authors observed that the axial force applied by the tool, the rotational speed of the tool, and the feed rate are decisive parameters influencing the strength of the bond.…”

“…Following [3,10], feed rates of 225 mm min −1 , 240 mm min −1 , 400 mm min −1 , 560 mm min −1 , and 600 mm min −1 were tested for the combination of PA6-GF30 with EN AW-6082-T6. The nominal temperatures were set to 260°C and 290°C.…”

Influence of the laser-based surface modification on the bond strength for friction press joining of aluminum and polyethylene

“…Friction press joining was first described by Wirth et al [4] using the example of joining aluminum with polyamide. The focus of the study was to identify the influence of the surface topology of the metallic joining partner on the bond strength.…”