Additive manufacturing of ceramics with biomimetic damage tolerance
In a recent article published in the journal Additive manufacturingthe researchers discussed three-dimensional ceramic composite printing with a biomimetic curing design.
Study: 3D printed ceramic composite with biomimetic curing design. Image Credit: bymandesigns/Shutterstock.com
Creating damage-tolerant ceramic composites has been found to be effective in mimicking the brick-and-mortar structure of mother-of-pearl. Despite the fact that nacre-inspired ceramic composites exhibit good characteristics, the discontinuous ceramic phase of bioinspired composites causes stress concentrations at the soft/hard interface, which decreases their bearing capacity.
Therefore, research on bi-continuous phase ceramic composites is anticipated. Damage-tolerant interpenetrating phase composites (IPCs) have been the subject of several studies so far.
Damage tolerant ceramic composites with complex geometries or unique designs are in high demand for a variety of applications. However, due to mold shape limitations, conventional processing techniques such as ice modeling or freeze molding are unable to provide geometric freedom for the fabrication of ceramic composites. 3D printing, also known as additive manufacturing, has created new possibilities for creating ceramic composites with complex geometric structures.
Digital Light Processing (DLP) is gradually becoming the best AM technique for manufacturing high-performance, geometrically perfect, defect-free parts with a tolerable level of precision and a passable level of surface quality. Due to their exceptional chemical and mechanical stability, damage resistant and high toughness ceramics are essential for a wide range of practical applications. However, current processing techniques make it impossible to produce parts with complex or custom geometries due to mold shape limitations.
About the study
In this study, the authors discussed a promising technique for creating geometrically challenging ceramic composite parts with exceptional damage tolerance using additive manufacturing (AM) and state-of-the-art biomimetic curing design. As-made ceramic composites were used to provide extraordinary toughness gains that were 116 times similar to pure ceramic, avoided catastrophic failure, and had unique geometries that could not be produced using conventional methods. standard.
The team proposed a viable strategy for the utility of additive manufacturing to create ceramic composites having bi-continuous zirconia/epoxy phases that were geometrically challenging and damage tolerant. Due to its widely known triply periodic minimum surface structure (TPMS) and large surface area, inspired by the cocksfoot club, it was specifically chosen as a continuous ceramic scaffold.
The researchers fabricated the proposed scaffolds using an in-house digital light processing (DLP) printer and were then infiltrated with an epoxy polymer that acted as the soft phase. These bio-inspired composites demonstrated exceptional damage tolerance in terms of toughness. There was a demonstration of a unique application in dental restorations.
In restorative dentistry, IPCs with 75 volume % zirconia have been constructed as the dentin of posterior or anterior pontic bridges. Dense zirconia could also be used as hard external enamel. While the graded ceramic wall thickness increased linearly from 0.3 to 0.7 mm, resulting in a graded stress distribution with peak stress concentrations around the top surface, the ceramic wall thickness of uniform composites at 34.6% by volume was maintained at 0.5 mm.
As a result, the compressive stresses dispersed evenly in the ceramic structure. As a result, the graded scaffold of the composite was progressively broken along the direction of compression as the stress increased from 0.2 to 0.6, while the fractures propagated into the thicker surface.
The experimental results revealed that the strength of the uniform and graded composites increased by 84 and 213%, respectively, compared to the sintered ceramic, while the Young’s modulus was only slightly increased. Additionally, it was found that the hardness of uniform and graded composites increased significantly by 30 and 116 times, respectively.
In conclusion, this study elucidated a potential technique for creating complex geometries of damage-tolerant ceramic composites using 3D printing and innovative biomimetic design. The bi-continuous architecture of the mantis shrimp, which was mimicked, provided the produced ceramic composites with extraordinary toughness and load-bearing capacity.
Experimental and theoretical research has been carried out to examine the mechanisms of hardening of the biomimetic structure. The authors mentioned that the created composites have enormous potential for dental restorations. More importantly, they predicted that the proposed strategy could be extended to the manufacture of additional high-performance engineering materials, opening the door to new applications in a wide range of industries, including tissue engineering, automotive and aerospace and energy devices.
The authors also stated that these AM-treated bioinspired ceramic composites open up exciting possibilities for applications requiring customization.
Sun, J., Yu, S., Wade-Zhu, J., et al. 3D printed ceramic composite with biomimetic curing design. Additive Manufacturing 103027 (2022). https://www.sciencedirect.com/science/article/abs/pii/S2214860422004195