Documents published in Scipedia

• Comparative analysis of processing conditions and characterization of dissimilar metal–thermoplastic composite Joints

  S. Dasilva, Á. Rodríguez, P. Rodríguez Alonso, B. Gomes, F. Ares-Blanco, C. Blanco Veiga, S. Trillo Lago

  Materiales Compuestos (Online first).

  
  

  Abstract

  The demand for lightweight and high-strength materials across various industries has driven research into hybrid structures that combine the mechanical advantages of metals with the low weight and strength of carbon fiber-reinforced composites. The use of thermoplastic composites additionally enables disassembly and reuse at the end of the service life. Furthermore, the metal-composite joining process and the thermoplastic CFRP processing could potentially be achieved in a single step, resulting in reduced manufacturing cycle times and overall higher productivity. However, several challenges must be addressed, such as differences in the coefficients of thermal expansion, the influence of the composite processing parameters on the metallic material and its surface treatment, and the potential formation of galvanic couples. This study investigates different manufacturing methods for dissimilar or multi-material joints: automated fiber placement (AFP) and thermoforming. A comparison is presented based on the manufacturing parameters, which were adjusted to maximize joint strength for each process.A cross-sectional optical microscopy analysis was carried out to evaluate the joint interface and the interaction between the surface treatment and the thermoplastic resin matrix layer, which is responsible for the adhesive bond between both components. In addition, mechanical testing was conducted to assess the influence of processing parameters, establishing a joint design route for optimized performance evaluation. The conclusions demonstrate that the polymer layer at the interface plays a key role in compensating for differences in thermal expansion coefficients, leading to enhanced mechanical performance of the joint. The advantages and limitations of each manufacturing method are discussed in this work.

  Abstract
  The demand for lightweight and high-strength materials across various industries has driven research into hybrid structures that combine the mechanical advantages of metals [...]

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• Monitoring of process parameters during the forming of SMC materials, mechanical an thermal properties (COMPCERTO Project)

  P. Rodríguez Alonso, Á. Rodríguez, R. Estal Vera, S. Dasilva

  Materiales Compuestos (2025). Vol. 09 - Comunicaciones MatComp25 (2025), (Núm. 1 - Fabricación y Aplicaciones Industriales), 42

  
  

  Abstract

  In recent times, polymer matrix composite material technologies have undergone a genuine revolution, driven by the surge in demand—particularly in the transportation and energy sectors. Composites are being increasingly incorporated due to the significant weight reduction they enable in structural components, which in turn leads to a decrease in energy consumption in transportation as a result of this weight savings. Ambitious EU sustainability policies (such as the EU Green Deal or the New Industrial Strategy) are further accelerating this shift toward efficient and sustainable solutions, with a significant impact on the transportation sector, especially the automotive industry—both in conventional and emerging propulsion systems (the use of lightweight materials is expected to increase from the current 30% to 70% by 2030, with composites accounting for approximately 20%). However, the automotive sector is one of the most demanding in terms of processing times. Therefore, the optimization and monitoring of processing parameters through embedded sensors in molds is presented as a valuable tool for adapting processing times and enabling continuous quality control of parts. This paper presents the results obtained within the framework of the COMPCERTO project, which aims to develop solutions that facilitate the optimized manufacturing of components with structural requirements through Sheet Molding Compound (SMC) thermoforming processes. To achieve this, the implementation of sensors for monitoring curing, pressure, and temperature in molds is proposed, enabling the acquisition of representative values at critical points and in real time for the phenomena occurring during the thermoforming of parts in the press. Preliminary tests are carried out to optimize the curing cycle in order to determine the most suitable manufacturing parameters, and based on the results, a Design of Experiments (DoE) is proposed. Finally, mechanical, thermal, and microstructural characterizations are performed on the tests defined in the DoE. This will generate a database that serves to correlate the real-time data obtained from the parts with potential defects in the SMC components.

  Abstract
  In recent times, polymer matrix composite material technologies have undergone a genuine revolution, driven by the surge in demand—particularly in the transportation [...]

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• Fabrication and characterisation of thermoplastic multi-material FML (fibre-metal laminates) structures

  Á. Rodríguez, P. Rodríguez Alonso, S. Dasilva

  Materiales Compuestos (Online first).

  
  

  Abstract

  The increase in both competitiveness and new environmental regulations has created a need within the transport sector to develop new high value-added and differentiated products in an efficient and sustainable manner. In this context, there is a growing need to develop new multi-material components, understood as dissimilar joints between lightweight metals and thermoplastic composite materials, especially for use in high-stress areas of the component. The use of Fibre-Metal Laminates (FMLs) offers, in addition to improved strength compared to lightweight metal alloys such as aluminum, enhanced resistance to mechanical fatigue and impact when compared to monolithic composite materials, combining the properties of both materials. The development of this type of laminate (FML) has traditionally focused on thermoset composites, which have a limited lifespan due to their inability to be reprocessed, as well as longer manufacturing times. For this reason, the COMIC project has studied different manufacturing methodologies for FMLs with a thermoplastic matrix, achieving lightweight and sustainable components simultaneously. This work presents a study of various surface treatments aimed at increasing the surface energy of the metal, which promotes physical and chemical anchoring between the metal and the composite. Additionally, different FML manufacturing methodologies have been explored, incorporating the various surface treatments. Finally, the optimal parameters and treatments have been selected for the production of FML laminates (PA6-aluminum composite) that maximize interlaminar strength and mechanical performance, with a comparison made against monolithic composite materials.

  Abstract
  The increase in both competitiveness and new environmental regulations has created a need within the transport sector to develop new high value-added and differentiated products [...]

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