Manufacturing Gradient Materials via Extrusion-Based 3D Printing: A Methodology Based on Transport Relaxation Mechanics Model

In recent years, the field of materials science has witnessed a paradigm shift, transitioning from the conventional use of homogeneous materials towards the innovative realm of gradient composite materials. This transformation has been significantly catalyzed by the rapid advancements in additive manufacturing technologies, making gradient materials a focal point of contemporary research. This paper presents a comprehensive exploration into the development of a state-of-the-art 3D printer and a specialized dual-component printhead tailored for the precise manufacturing of gradient materials. Accompanying this technological innovation, we introduce a sophisticated design software founded on voxelized digital models and establish a robust viscoelastic transport relaxation mechanical model. Additionally, we propose a model-based control methodology that achieves unparalleled precision in material extrusion control, validated through meticulous experimental and parameter identification processes. To underscore the practical implications of gradient materials, we design a representative mechanical application case, effectively demonstrating their remarkable efficacy in mitigating stress concentration issues. The validity of our approach is rigorously substantiated through a combination of simulation and mechanical experiments. In essence, this paper serves as a pioneering contribution to the domain of continuous gradient materials via 3D printing, effectively addressing the pivotal challenge of transport accuracy and laying a solid foundation for the future development of this cutting-edge field.