3D-printed oblique honeycomb Al2O3/SiCw structure for electromagnetic wave absorption

2020

Polymers

To obtain excellent electromagnetic wave (EMW) absorption materials, the design of microstructures has been considered as an effective method to adjust EMW absorption performance. Owing to its inherent capability of effectively fabricating materials with complex various structures, three-dimensional (3D) printing technology has been regarded as a powerful tool to design EMW absorbers with plentiful microstructures for the adjustment of EMW absorption performance. In this work, five samples with various microstructures were prepared via fused deposition modeling (FDM). An analysis method combining theoretical simulation calculations with experimental measurements was adopted to investigate EMW absorbing properties of all samples. The wood-pile-structural sample possessed wider effective absorption bandwidth (EAB; reflection loss (RL) < − 10 dB, for over 90% microwave absorption) of 5.43 GHz and generated more absorption bands (C-band and Ku-band) as compared to the honeycomb-structural sample at the same thickness. Designing various microstructures via FDM proved to be a convenient and feasible method to fabricate absorbers with tunable EMW absorption properties, which provides a novel path for the preparation of EMW absorption materials with wider EAB and lower RL.

“…As shown in Figure 5 c,d, the values of

varied in the range of 0.95–1.05, 0–0.1, and 0–0.12, respectively, indicating the RL values were mainly determined by the complex relative permittivity

The measured frequency dependence of

and

is shown in Figure 5 a. As shown in Figure 5 a, the values of

Section: Resultsmentioning

confidence: 99%

“…For non-magnetic materials, the

and

values of the complex relative permeability were 1 and 0, respectively [ 40 ]. As shown in Figure 5 c,d, the values of

varied in the range of 0.95–1.05, 0–0.1, and 0–0.12, respectively, indicating the RL values were mainly determined by the complex relative permittivity

The measured frequency dependence of

and

is shown in Figure 5 a.…”

Section: Resultsmentioning

confidence: 99%

Electromagnetic Wave Absorption Properties of Structural Conductive ABS Fabricated by Fused Deposition Modeling

Lai

2020

Polymers

“…As is well-known, the impedance matching and attenuation constant are regarded as the two most critical factors for the EMW absorption properties of absorbers [ 71 ]. As for the ideal condition of impedance matching, which determines the capability of incident waves entering into an absorber, |

| or |

| was expected to be closer to 1 or 0 [ 72 ]. The |

| values of the samples at the optimal thickness corresponding to RL-min were calculated according to equation (2), as shown in Figure 3 a.…”

Section: Resultsmentioning

confidence: 99%

Effects of Carbonyl Iron Powder (CIP) Content on the Electromagnetic Wave Absorption and Mechanical Properties of CIP/ABS Composites

Lai

2020

Polymers

Three-dimensional (3D) printing technology has proven to be a convenient and effective method to fabricate structural electromagnetic wave (EMW) absorbers with tunable EMW absorption properties. To obtain a functional material with strong EMW absorbing performance and excellent mechanical properties for fused deposition modeling (FDM) 3D printing technology, in this work, carbonyl iron powder (CIP)/acrylonitrile-butadiene-styrene copolymer (ABS) composites with different CIP contents were prepared by the melt-mixing process. The effects of the CIP content on the EMW absorption and mechanical properties of CIP/ABS composites were investigated. The CIP/ABS composite with a CIP content of 40 wt.% presented the lowest reflection loss (RL) of −48.71 dB for the optimal impedance matching. In addition, this composite exhibited optimal mechanical properties due to the good dispersion of the CIPs in the matrix ABS. Not only were the tensile and flexural strength similar to pure ABS, but the tensile and flexural modulus were 32% and 37% higher than those of pure ABS, respectively. With a CIP content of 40 wt.%, the CIP/ABS composite proved to be a novel functional material with excellent EMW absorbing and mechanical properties, providing great potential for the development of structural absorbers via FDM 3D printing technology.

“…Moreover, controllable angles of honeycomb structure creates opportunity for adjusting the microwave absorption capacity through dielectric loss, impedance match and internal multiple scattering. For example, the Al 2 O 3 /SiC whisker composites with the angle of 30° which showed in Figure 2 exhibited an excellent EMW absorption performance and reached a minimum reflection coefficient value of −63.65 dB (99.9999% absorption) 34 . Recently, special attention has been paid to additive manufacture technology.…”

Section: Structure Designmentioning

confidence: 99%

“…(A) actual photograph of the specimen; (B) SEM images of 3D printed Al 2 O 3 /SiC w whiskers composites 34 …”

Section: Structure Designmentioning

confidence: 99%

A review: 3D printing of microwave absorption ceramics

Int J Applied Ceramic Tech

2020

Along with extensive research on the 3D printing and microwave absorption ceramics, 3D printing technology provides a great possibility for microwave absorption ceramics with arbitrary shapes in a faster, cheaper and more flexible way. This review focuses on the latest evolution in the raw materials, the structure design and the advanced additive manufacturing technologies of 3D printing microwave absorption ceramics. Firstly, the representative raw materials are divided into three categories, including ceramic powder, cermet powder and precursor resin. In addition, additives give rise to improvement of microwave absorption properties of ceramics. Secondly, based on two attenuation theories, structure design makes further efforts to enhance the microwave absorption performance of ceramics. Finally, comparisons are made between diversified manufacturing technologies to facilitate the selection of the best ones for different application in practical use. This study presents a summary of research that has been conducted to produce microwave absorption ceramics by additive manufacturing.