Digital light processing of Si-based composite ceramics and bulk silica ceramics from a high solid loading polysiloxane/SiO2 slurry

Author(s):  
Chong He ◽  
Xinger Liu ◽  
Cong Ma ◽  
Yueqi Cao ◽  
Feng Hou ◽  
...  
2021 ◽  
Author(s):  
Ping Yang ◽  
Zhenfei Sun ◽  
Shengwu Huang ◽  
Jun Ou ◽  
Shanghua Wu

Abstract Due to high light absorption and high refractive index of silicon nitride (Si3N4) ceramic, it is difficult to prepare Si3N4 slurry with favourable curing ability, high solid loading and low viscosity at the same time, and thus the high quality Si3N4 parts are hard to fabricate via Digital Light Processing (DLP). In this paper, oxidation process was used to enhance the curing behavior of Si3N4 slurry, and then silane coupling agent (KH560) was used to improve the rheological properties of the oxidized Si3N4 slurry. The effect of Si3N4 slurry with oxidation and modification on its rheological behavior, light absorption, curing ability and stability have been systematically investigated. A Si3N4 slurry with abundant photocuring ability, high solid loading, low viscosity and reliable stability was fabricated by the oxidized (1h) and KH560 (1wt.%) modified Si3N4 powders, and the dense Si3N4 ceramic parts were produced by this slurry via DLP 3D printing. Subsequently, the influence of oxidation and modification on microstructure, mechanical properties and thermal conductivity have been investigated. Finally, the performances of the DLP 3D printed samples are close to the isostatic cool pressing (ICP) fabricated samples. Consequently, DLP has well potential to fabricate high-performance Si3N4 ceramics.


Author(s):  
Zhongqi Zhu ◽  
Zhiyuan Gong ◽  
Piao Qu ◽  
Ziyong Li ◽  
Sefiu Abolaji Rasaki ◽  
...  

AbstractInkjet printing is a promising alternative for the fabrication of thin film components for solid oxide fuel cells (SOFCs) due to its contactless, mask free, and controllable printing process. In order to obtain satisfying electrolyte thin layer structures in anode-supported SOFCs, the preparation of suitable electrolyte ceramic inks is a key. At present, such a kind of 8 mol% Y2O3-stabilized ZrO2 (8YSZ) electrolyte ceramic ink with long-term stability and high solid loading (> 15 wt%) seems rare for precise inkjet printing, and a number of characterization and performance aspects of the inks, such as homogeneity, viscosity, and printability, should be studied. In this study, 8YSZ ceramic inks of varied compositions were developed for inkjet printing of SOFC ceramic electrolyte layers. The dispersing effect of two types of dispersants, i.e., polyacrylic acid ammonium (PAANH4) and polyacrylic acid (PAA), were compared. The results show that ultrasonic dispersion treatment can help effectively disperse the ceramic particles in the inks. PAANH4 has a better dispersion effect for the inks developed in this study. The inks show excellent printable performance in the actual printing process. The stability of the ink can be maintained for a storage period of over 30 days with the help of initial ultrasonic dispersion. Finally, micron-size thin 8YSZ electrolyte films were successfully fabricated through inkjet printing and sintering, based on the as-developed high solid loading 8YSZ inks (20 wt%). The films show fully dense and intact structural morphology and smooth interfacial bonding, offering an improved structural quality of electrolyte for enhanced SOFC performance.


2017 ◽  
Vol 54 (9) ◽  
pp. 576-581
Author(s):  
Seizo Obata ◽  
Sosuke Azuma ◽  
Kenji Tateishi ◽  
Yasuhiro Shinoda ◽  
Michiyuki Yoshida ◽  
...  

2007 ◽  
Vol 280-283 ◽  
pp. 751-752 ◽  
Author(s):  
Sheng Cheng ◽  
Jiang Hong Gong ◽  
Zhong Tai Zhang ◽  
Zi Long Tang

A novel process, gel-tape-casting, is employed to fabricate LSGM thin dense sheets in aqueous AM system. The influences of powder properties, dispersant and other additives were discussed and relevant processing parameters were also explored. The slurry of LSGM with a high solid loading about 33 vol.% was successfully obtained.


2019 ◽  
Vol 45 (9) ◽  
pp. 11549-11557 ◽  
Author(s):  
Zhangwei Chen ◽  
Junjie Li ◽  
Chengbo Liu ◽  
Yu Liu ◽  
Junyi Zhu ◽  
...  

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1790 ◽  
Author(s):  
Pablo G. del Río ◽  
Patricia Gullón ◽  
F.R. Rebelo ◽  
Aloia Romaní ◽  
Gil Garrote ◽  
...  

Corn stover is the most produced byproduct from maize worldwide. Since it is generated as a residue from maize harvesting, it is an inexpensive and interesting crop residue to be used as a feedstock. An ecologically friendly pretreatment such as autohydrolysis was selected for the manufacture of second-generation bioethanol from corn stover via whole-slurry fermentation at high-solid loadings. Temperatures from 200 to 240 °C were set for the autohydrolysis process, and the solid and liquid phases were analyzed. Additionally, the enzymatic susceptibility of the solid phases was assessed to test the suitability of the pretreatment. Afterward, the production of bioethanol from autohydrolyzed corn stover was carried out, mixing the solid with different percentages of the autohydrolysis liquor (25%, 50%, 75%, and 100%) and water (0% of liquor), from a total whole slurry fermentation (saving energy and water in the liquid–solid separation and subsequent washing of the solid phase) to employing water as only liquid medium. In spite of the challenging scenario of using the liquor fraction as liquid phase in the fermentation, values between 32.2 and 41.9 g ethanol/L and ethanol conversions up to 80% were achieved. This work exhibits the feasibility of corn stover for the production of bioethanol via a whole-slurry fermentation process.


2020 ◽  
Vol 8 (34) ◽  
pp. 13007-13018
Author(s):  
Li Xu ◽  
Wen-Chao Li ◽  
Jiayu Xin ◽  
Sen-Jia Zhang ◽  
Bing-Zhi Li ◽  
...  

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