KIMS improves joint strength of thermoplastic carbon fiber composites for aerospace
A Korean research team improved the bonding strength of carbon fiber composites by 30.8% using a nanocomposite aerogel in an induction joining process.
The Korea Institute of Materials Science (KIMS) has achieved a 30.8% improvement in the joint strength of thermoplastic carbon fiber composites, materials known for their lightweight and robust properties, used in automotive and aerospace applications. The research, led by Principal Researcher Oh Young-seok and Senior Researcher Kim Jin-soo, developed an induction joining technology that employs a nanocomposite aerogel to rapidly and uniformly heat and join these composites. The findings were published in the journal "Advanced Composites and Hybrid Materials" on September 2.
Thermoplastic carbon fiber composites, which combine high-strength carbon fibers with thermoplastic polymers, are valued for their ability to soften and reshape with heat. The induction joining method traditionally used for these materials involves creating a magnetic field to induce a current within the carbon fibers, heating the joint area. However, challenges arise due to uneven current flow and varying magnetic field positions, leading to inconsistent joint quality.
The KIMS team addressed these issues by developing a new joining material that efficiently transfers heat between the composites. They created a nanocomposite aerogel by mixing carbon nanotubes (CNTs), magnetic iron oxide (Fe3O4), and polyamide 6 (PA6), ensuring even distribution through a freeze-drying process. This material, when applied between the joint surfaces, allows for rapid and uniform heating during induction, enhancing the bonding process.
Experimental results demonstrated that the new material increased the initial heating rate by up to 94.6% and reduced the time to reach the necessary joining temperature by 57%. The uniform heating allowed the molten resin to spread effectively, with CNTs acting as microscopic reinforcements, further strengthening the joint.
A patent has been filed for this technology, and the research team plans to develop an AI-based system to optimize temperature distribution and process conditions during induction heating. Principal Researcher Oh Young-seok highlighted the significance of combining electrical and magnetic heating in a single material to improve heating rate, temperature uniformity, and joint strength, with potential applications in automotive and aviation composite joining processes.
Source: Carbon Fiber Feed