Material Extrusion of Structural Polymer-Aluminum Joints-Examining Shear Strength, Wetting, Polymer Melt Rheology and...

Area of Science:

• Additive Manufacturing
• Materials Science
• Polymer Engineering

Background:

• Additive manufacturing enables customized, sustainable, and lightweight polymer-metal structures.
• Reliability and reproducibility of additively manufactured joints remain significant challenges.
• Joining common thermoplastic polymers (ABS, PETG, PLA) to aluminum substrates is explored.

Purpose of the Study:

• To investigate the suitability of ABS, PETG, and PLA for additive manufacturing of polymer-aluminum joints.
• To determine optimal thermal processing conditions by examining polymer melt rheology, wetting, and tensile shear strength.
• To evaluate the long-term performance of these joints under environmental aging.

Main Methods:

• Material extrusion additive manufacturing was used to join ABS, PETG, and PLA to grit-blasted aluminum.
• Polymer melt rheology, wetting behavior, and tensile single-lap-shear strength were characterized.
• Joints were aged for up to 100 days in two moderate environments to assess durability.

Main Results:

• PETG demonstrated the highest suitability for creating structural polymer-aluminum joints under the tested conditions.
• ABS-aluminum joints (fresh) and PLA-aluminum joints (aged) did not meet structural joint requirements.
• Rheological properties of polymers and wetting experiments aided in predicting joint strength.

Conclusions:

• PETG is the most suitable polymer for structural additive manufacturing of polymer-aluminum joints in this study.
• Polymer rheology and wetting behavior are key indicators for evaluating the potential of polymer-aluminum joints.
• Understanding these properties is crucial for reliable and reproducible additive manufacturing of hybrid structures.