Nickel-Aluminum Thermal Spray Coatings as Adhesion Promoter and Susceptor for Inductively Joined Polymer-Metal Hybrids

Abstract

Hybrid joints of metal- and fiber-reinforced-polymer offer great potential for lightweight applications. Thereby, a fast and reliable joining process is mandatory for mass-production applications. To this end, this study assesses inductive spot-joining in combination with prior thermal spray coating of the metal adherent. A nickel–aluminum 95/5 coating was applied to achieve high adhesion through mechanical interlocking and to act as susceptor for the inductive joining process. The joint strength was assessed with lap shear specimens consisting of EN AW-6082 aluminum alloy and glass fiber reinforced polyamide 6 or polypropylene, respectively. The joints were further investigated in terms of heating time and hygrothermal cyclic loading. The results showed that significant time savings for the joining process as well as strong adhesion were achieved due to the coating. Moreover, the high strengths were even preserved under hygrothermal cyclic loading.

Pin-Shaped Surface Structures Generated by Laser Single Pulse Drilling for High-Strength Interfaces in Thermally Joined Polymer–Metal Hybrids

“…After solidification, it interlocks the metal surface microstructure, thus creating a strong bonding. The thermal energy is transferred to the metal, e.g., by a heated stamp ( Figure 1 a) [ 4 , 5 , 6 , 7 , 8 ], a laser beam ( Figure 1 b) [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ], an induction coil ( Figure 1 d) [ 19 , 20 , 21 , 22 ] or a rotating pin ( Figure 1 f) [ 23 , 24 , 25 , 26 , 27 ]. Techniques for creating the heat directly in the joining zone are direct laser joining using polymers with sufficient transparency ( Figure 1 c) [ 9 , 28 ] or ultrasonic welding ( Figure 1 e) [ 8 , 29 , 30 , 31 , 32 ].…”

Nanoscale‐Sculptured Al Microparticles as Universal Hierarchical Adhesion Promoters

“…[10] Different approaches like plasma treatment, ion-beam irradiation, or adhesion promoter are commonly used to improve the adhesion between the two materials by increasing the chemical bond strength. [11][12][13] Plasma treatment is an effective way to activate a polymer surface, especially those with low surface energy, where the activated functional groups can form bonds with another polymer. [11] Disadvantages of plasma treatment are the system dependency and the short lifetime of the activated surface, which means that the same flow rate, gas pressure, and power input may not produce the same level of activation of the surfaces.…”