Influence of Aluminum Laser Ablation on Interfacial Thermal Transfer and Joint Quality of Laser Welded Aluminum–Polyamide Assemblies

Adham Al-Sayyad,Laurent Houssiau,Peter Plapper,Regis Vaudémont,Pierre Hirchenhahn,Julien Bardon

doi:10.3390/coatings9110768

Adham Al-Sayyad, Laurent Houssiau + Show 4 more

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https://doi.org/10.3390/coatings9110768

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Abstract

Laser assisted metal–polymer joining (LAMP) is a novel assembly process for the development of hybrid lightweight products with customized properties. It was already demonstrated that laser ablation of aluminum alloy Al1050 (Al) prior to joining with polyamide 6.6 (PA) has significant influence on the joint quality, manifested in the joint area. However, profound understanding of the factors affecting the joint quality was missing. This work investigates the effects of laser ablation on the surface properties of Al, discusses their corresponding impact on the interfacial thermal transfer between the joining partners, and evaluates their effects on the joint quality. Samples ablated with different parameters, resulting in a range from low- to high-quality joints, were selected, and their surface properties were analyzed by using 2D profilometry, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). In order to analyze the effects of laser ablation parameters on the interfacial thermal transfer between metal and polymer, a model two-layered system was analyzed, using laser flash analysis (LFA), and the thermal contact resistance (TCR) was quantified. Results indicate a strong influence of laser-ablation parameters on the surface structural and morphological properties, influencing the thermal transfer during the laser welding process, thus affecting the joint quality and its resistance to shear load.

Highlights

Joining metals to polymers has gained prominent interest among researchers and industries because of its ability to produce lightweight hybrid structures with tailored properties
This research aims at understanding the effects of surface properties on the interfacial thermal transfer between laser ablated Al 1050 joined to polyamide 6.6 (PA) 6.6 using laser-beam welding
The link between the aluminum surface characteristics after laser ablation and the shear resistance of dissimilar joints formed by laser welding of ablated aluminum with polyamide was investigated

Summary

Introduction

Joining metals to polymers has gained prominent interest among researchers and industries because of its ability to produce lightweight hybrid structures with tailored properties. Conventional metal–polymer joining methods, such as adhesive bonding, mechanical fastening, friction stir welding, and ultrasonic joining, have their drawbacks, as they either require high processing time, involve hazardous chemicals, cause excessive tool wear, involve geometrical constrains, or require the addition of weight to the component. The thermal joining of metals to polymers is challenging because of the significant difference of the thermal properties and melting temperatures of both materials. Researchers [3,4,5,6,7,8,9,10,11,12] reported the effects of several surface pretreatments on LAMP, including mechanical, chemical, electrochemical, and laser pretreatments for metals, as well as plasma and UV ozone pretreatment for polymers. LAMP is a thermal joining process, the effect of surface pretreatments on the thermal transfer between the joining partners during the laser welding process, and on the joint quality, has not been investigated

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