Abstract

Fibre-reinforced polymer composite materials are leading candidates as component materials to improve the efficiency and sustainability of many transport modes and specially in new vehicles based on electric mobility where weight is also an important requirement. The advantages of high-performance composites are numerous: they include lighter weight and reduced assembly costs due to high level of integration potential. This translates into greater weight savings resulting in improved performance, greater payloads, fuel or battery energy savings and emissions reductions. However, the manufacturing processes to provide high level of integration are still a challenge as the process becomes more complex in terms of materials preparation (cutting, stacking, etc), 3D preforming and toolings involved. In this context, Tecnalia, Gestamp and other partners have recently developed a suspension link, with the following features: Lightweight CFRP concept despite of the very high demanding mechanical loads requirements Fast stacking, cutting and 3D net shape preforming including also the corresponding advanced toolings and equipment One shot RTM and highly integrated concept to optimize the mechanical performance and reduce the process steps and joining operations

Abstract

Nowadays, the aeronautical sector use composite materials reinforced with high performance fibers. In this field, the composites of thermoplastic matrix (TPCs) is reinforced with continuous carbon fibers wich combine both high strength and lightness thus offering a great potential to replacement, at least partially, the metal alloys. The thermoplastic matrix allows reducing manufacturing costs and minimizing recycling problems. The integration of TPCs sometimes forces to combine pieces which are very different in composition, forming a multimaterial.

During the development of the research , the manufacturing and physical-mechanical characterization of the CF-PEEK composite material and the union of said material with titanium was carried out.

Firstly, the characterization and optimization of the press forming process of the monolithic CF-PEEK has been developed. The characterization was carried out through DSC and TGA tests, mechanical tensile tests according to the standard UNE-EN 527-5 and microscopic analysis.

Then, the CF-PEEK-Ti joints were made and evaluated.In order to improve the quality of the joints has been used Ti-6Al-4V with two surface treatments (shot blasting and laser texturing) and enrich the surface with PEEK film.The mechanical characterization was carried out through the SLJ (Single Lap Joint) test according to the standard ASTM D5868.

The results have shown how the laser treatment improves the quality of the joint, achieving the highest efficiency by enriching the surface with PEEK film. The viability of multi-material joints has been demonstrated through direct production in the press.