At IRDL; LMS, Mohamed Daly explored next-generation composite materials produced through 3D printing.
The Essentials: At IRDL; LMS, Mohamed Daly explored next-generation composite materials produced through 3D printing.
Mohamed Daly, researcher at IRDL; LMS (Institut National Polytechnique de Bretagne).
Thesis defended in 2025 at the doctoral school École doctorale Sciences pour l'ingénieur et le numérique.
Listed in the ABES/STAR network, this thesis meets the rigor criteria of French higher education.
Context and Research Problem
3D printing is transforming manufacturing methods by enabling the design of complex geometries and the rapid production of parts suited to various sectors, notably aerospace, automotive, and medical. This technology offers notable advantages, but it also faces challenges, such as warping of printed parts and production rates often lower than those of traditional manufacturing methods. Within this context, Mohamed Daly's thesis focuses on optimizing the mechanical performance of composite materials, particularly those based on thermoplastics reinforced with carbon fibers and nanoceramics. This research work aims to address the need to improve the strength and durability of materials used in additive manufacturing, while limiting defects such as warping and residual stresses.
The main objective of this research is to develop next-generation composite materials capable of meeting the high mechanical requirements of industrial applications. Optimizing printing parameters emerges as a solution to counter the current limitations of 3D printing technology. The materials studied include thermoplastic polymers such as ABS, CF-PETG, and Aerosil-reinforced polycarbonate, selected for their mechanical properties and their suitability for 3D printing.
Methodology
Daly's methodology relies on an approach combining practical experiments and numerical modelling. Tests were carried out to evaluate the behavior of composite materials under different environmental conditions, with an emphasis on the influence of temperature on mechanical properties. Analysis techniques include dynamic tests that provide data on the strength and durability of the materials.
The study also incorporated statistical methods to analyze the experimental results. Printing parameters, such as reinforcement type, infill patterns (rectilinear, honeycomb), and infill rates (20%, 50%, 75%, and 100%), were systematically varied to assess their impact on the performance of the printed parts. Scanning electron microscopy (SEM) was used to examine the microstructure of the materials and identify potential defects that could affect their integrity.
Key Findings
The results of this research reveal that the choice of reinforcement type and infill pattern configuration play a determining role in the mechanical properties of 3D-printed composite materials. Optimized infill configurations significantly reduce manufacturing defects, such as warping and residual stresses, which are commonly encountered problems in 3D printing.
Analysis of the composite materials showed that the use of carbon fibers strengthens the resistance of thermoplastics, while the incorporation of nanoceramics improves stiffness and durability. The tests revealed a notable improvement in mechanical performance, with samples showing increased resistance under dynamic load conditions. These advances suggest that optimized composite materials could potentially rival traditional materials used in the most demanding applications.
The experimental data also indicate that optimizing printing parameters could reduce production costs. By improving the mechanical performance of materials, companies could benefit from reduced waste and increased market competitiveness.
Discussion and Outlook
The research conducted by Mohamed Daly makes a significant contribution to advancing knowledge in the field of composite materials and 3D printing. The results obtained pave the way for potential applications in industrial sectors where mechanical performance is paramount. However, implementing these new technologies in production processes requires particular attention.
The challenges associated with integrating optimized composite materials into existing production lines raise important questions. Companies must consider the investments needed to adapt their infrastructure to the specific requirements of 3D printing. In addition, raising awareness and training end users on new manufacturing techniques are essential to ensuring successful adoption.
Future prospects for this research could include exploring new types of reinforcements and polymers, as well as evaluating the long-term durability of materials under varied usage conditions. Research into the environmental impact of 3D printing and composite materials could also become a priority area, aligning technological innovations with sustainable development goals.
The results of this thesis underscore the importance of interdisciplinary collaboration among researchers, engineers, and industry players to maximize the potential of 3D printing and composite materials in the future.
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Sources and Access
Mohamed Daly. Design and optimization of next-generation composite materials through additive manufacturing : towards revolutionary mechanical. Materials. École Nationale Supérieure de Techniques Avancées, 2025. English. ⟨NNT : 2025ESTA0016⟩. ⟨tel-05599497⟩