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

Abstract

Laser structuring is by far the most investigated metal surface-pretreatment method for creating adhesion in polymer–metal hybrids. Especially, cone-like protrusions show excellent wetting behaviour as well as high compound strength. However, the processing time is extremely high. Therefore, this paper assesses a process strategy for creating pin structures with scalable height by single pulse drilling with an Nd/YVO4 nanosecond laser system on EN AW-6082 aluminium alloy. The strength testing is carried out by butt-bonded hollow cylinder torsion. The samples are manufactured by heat-conduction thermal joining with polyamide 6. Ten different surface structures with two different ablation diameters are investigated and compared to cone-like protrusions in terms of processing time, wetting behaviour, shear strength and fracture behaviour. The experimental results show that pulse drilling pins structures with high aspect ratio reach-strength values close to cone-like protrusions but with 31 times higher processing rate.

Effect of Process Parameters on Joint Performance in Hot Pressure Welding of 6061 Aluminum Alloy to CF/PA66

“…At present, the commonly used method to improve the strength of metal/CFRTP hotpressure welded joints is to increase the macro-or micro-mechanical interlocking between both. The macro-mechanical interlocking is mainly conducted by prefabricating holes [35], raised structures [38,39], or combined use [40] on the metal surface. During the HPW process, the molten CFRTP matrix will flow into the holes, or the raised structures will be The main welding methods of metal/CFRTP include laser welding [11][12][13][14][15][16][17][18], friction welding [19][20][21][22][23][24][25][26][27], ultrasonic welding [28][29][30][31][32][33][34], hot pressure welding [35][36][37][38][39][40][41], and so on.…”

“…The macro-mechanical interlocking is mainly conducted by prefabricating holes [35], raised structures [38,39], or combined use [40] on the metal surface. During the HPW process, the molten CFRTP matrix will flow into the holes, or the raised structures will be The main welding methods of metal/CFRTP include laser welding [11][12][13][14][15][16][17][18], friction welding [19][20][21][22][23][24][25][26][27], ultrasonic welding [28][29][30][31][32][33][34], hot pressure welding [35][36][37][38][39][40][41], and so on. Among them, hot pressure welding (HPW) has the characteristics of simple equipment structure, environmental friendliness, ease of automation, etc., and has a broad development space and application prospect.…”

“…The results showed that the textured TC4 surface improved the wettability of molten CFRTP to TC4, thereby enhancing the tensile-shear force of the joint. Saborowski et al [39] used an Nd/YVO 4 nanosecond laser system to create a pin structure with scalable height through single-pulse drilling on 6082 aluminum alloy and connected it to polyamide 6 using HPW. The experimental results showed that pulse drilling pin structures show excellent wetting behavior.…”

“…At present, the commonly used method to improve the strength of metal/CFRTP hotpressure welded joints is to increase the macro-or micro-mechanical interlocking between both. The macro-mechanical interlocking is mainly conducted by prefabricating holes [35], raised structures [38,39], or combined use [40] on the metal surface. During the HPW process, the molten CFRTP matrix will flow into the holes, or the raised structures will be inserted into the CFRTP matrix and form an interlocking structure after cooling.…”