Microstructure and Mechanical Performance of Additively Manufactured Aluminum 2024-T3/Acrylonitrile Butadiene Styrene Hybrid Joints Using an AddJoining Technique

Abstract

AddJoining is an emerging technique that combines the principles of the joining method and additive manufacturing. This technology is an alternative method to produce metal–polymer (composite) structures. Its viability was demonstrated for the material combination composed of aluminum 2024-T3 and acrylonitrile butadiene styrene to form hybrid joints. The influence of the isolated process parameters was performed using the one-factor-at-a-time approach, and analyses of variance were used for statistical analysis. The mechanical performance of single-lap joints varied from 910 ± 59 N to 1686 ± 39 N. The mechanical performance thus obtained with the optimized joining parameters was 1686 ± 39 N, which failed by the net-tension failure mode with a failure pattern along the 45° bonding line. The microstructure of the joints and the fracture morphology of the specimens were studied using optical microscopy and scanning electron microscopy. From the microstructure point of view, proper mechanical interlocking was achieved between the coated metal substrate and 3D-printed polymer. This investigation can be used as a base for further improvements on the mechanical performance of AddJoining hybrid-layered applications.

Estimation of the Adhesion Interface Performance in Aluminum-PLA Joints by Thermographic Monitoring of the Material Extrusion Process

“…The single lap shear strength, τSLJ, increased with increasing substrate temperature, Ts, and decreasing layer height, dPo (cf. Figure 18), which is in conjunction with e.g., [8,14,17]. Additionally, the decrease in the average cooling rate, ̇, (0.5−1 ) , and preset contact angle, φcs,i, also led to a change in failure mode from adhesive to cohesive failure.…”

“…A tool to evaluate the local structure at the interface during the process is of fundamental interest, as the sequential deposition of the polymer, as well as temperature gradients within the substrate lead to time-dependent local variations in wetting and adhesion depending on the local processing conditions. The process parameters substrate temperature, T s , and layer height, d Po , which were varied in this study, are often adjusted depending on the use case and are expected to affect the adhesion interface performance (cf., e.g., [8,14,17]).…”

“…For the most common thermoplastics currently used in the ME process, Amancio-Filho et al [ 13 ] suggests substrate temperatures in between the extrusion, T e , and the crystallization temperature, T c , of the polymer to optimize the polymer–metal bonding. In their recent publications regarding the Addjoining ® process, Falck et al [ 14 , 15 ] applied a primer by spreading, e.g., an acrylonitrile butadiene styrene (ABS)-acetone solution onto the metal surface before the actual ME process is carried out. An improvement in single lap shear strength was observed for an increased extruder head velocity, primer thickness and decreased layer height [ 14 ].…”

“…In their recent publications regarding the Addjoining ® process, Falck et al [ 14 , 15 ] applied a primer by spreading, e.g., an acrylonitrile butadiene styrene (ABS)-acetone solution onto the metal surface before the actual ME process is carried out. An improvement in single lap shear strength was observed for an increased extruder head velocity, primer thickness and decreased layer height [ 14 ]. Chueh et al [ 16 ] generated, e.g., polylactic acid (PLA)-steel joints by ME of the polymer on a preheated (180 °C) structured metal substrate with undercuts.…”

Correction: Falck, R. et al. Microstructure and Mechanical Performance of Additively Manufactured Aluminum 2024-T3/Acrylonitrile Butadiene Styrene Hybrid Joints by AddJoining Technique. Materials 2019, 12, 864

“…The authors wish to make the following correction to the paper [1]. Due to identical data in Table 6 and Table 7, replace: These changes have no material impact on the discussion and conclusions of the paper.…”