Mechanical and dielectric properties of porous and wave-transparent Si3N4-Si3N4 composite ceramics fabricated by 3D printing combined with chemical vapor infiltration
Mechanical and dielectric properties of porous and wave-transparent Si3N4-Si3N4 composite ceramics fabricated by 3D printing combined with chemical vapor infiltration
复制标题
3D打印结合化学气相渗透制备多孔透波Si3N4-Si3N4复合陶瓷的机械和介电性能
DOI：
10.1007/s40145-019-0322-8
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发表时间：
2019-09-01
影响因子：
16.9
通讯作者：
Zhang, Litong
中科院分区：
文献类型：
--
作者：
Cheng, Zanlin;Ye, Fang;Zhang, Litong
采用3D打印结合低压化学气相渗透（CVI）技术制备了多孔Si 3 N4-Si 3 N4复相陶瓷。该技术可以有效提高多孔Si 3 N4陶瓷的可设计性，优化其力学性能和介电性能。研究了沉积时间、热处理等工艺参数对多孔Si 3 N4-Si 3 N4复相陶瓷显微结构和性能的影响。研究报告强调了以下几点：当CVI处理时间从0增加到12 h时，孔隙率从68.65%降低到26.07%，密度从0.99增加到2.02 g/cm 3。同时，介电常数从1.72逐渐增大到3.60，而介电损耗始终保持在0.01以下，表明多孔Si 3 N4-Si 3 N4复合陶瓷具有优良的电磁波透过性能。当沉积时间达到6 h时，抗弯强度达到最大值（47±2 MPa）。热处理后，孔隙率从26.07%增加到36.02%，介电常数从3.60增加到3.70，介电损耗仍保持在0.01以下。结果表明，多孔Si_3N_4-Si_3N_4复合陶瓷是一种很有前途的高温结构和透波材料。
Porous Si3N4-Si3N4 composite ceramics were fabricated by 3D printing combined with low-pressure chemical vapor infiltration (CVI). This technique could effectively improve the designability of porous Si3N4 ceramics and optimize the mechanical and dielectric properties. The effects of process parameters including the deposition time and heat treatment on the microstructure and properties of porous Si3N4-Si3N4 composite ceramics were studied. The study highlights following: When CVI processing time was increased from 0 to 12 h, the porosity decreased from 68.65% to 26.07% and the density increased from 0.99 to 2.02 g/cm3. At the same time, the dielectric constant gradually increased from 1.72 to 3.60; however, the dielectric loss always remained less than 0.01, indicating the excellent electromagnetic (EM) wave-transparent performance of porous Si3N4-Si3N4 composite ceramics. The maximum flexural strength of 47±2 MPa was achieved when the deposition time attained 6 h. After heat treatment, the porosity increased from 26.07% to 36.02% and the dielectric constant got a slight increase from 3.60 to 3.70 with the dielectric loss still maintaining lower than 0.01. It has been demonstrated that the porous Si3N4-Si3N4 composite ceramics are a promising structural and EM wave-transparent material suitable for high temperature service.