推 荐 人:鲁毓钜

文献信息1Fuks D, Shter G E, Mann–Lahav M, et al. Crack-free drying of ceramic foams by the use of viscous cosolvents [J]. Journal of the American Ceramic Society, 2010, 93(11): 3632–3636.

推荐理由:在泡沫陶瓷制备过程中,坯体干燥时的开裂是个非常严重的问题。这篇文章通过在陶瓷浆料中加入一定量非挥发性的共溶剂,比如丙二醇、甘油等,改变了坯体干燥过程的机理,制备出了干燥时不容易开裂的大尺寸泡沫陶瓷坯体。这种避免坯体干燥开裂的研究思路和方法,非常值得我们借鉴学习。

AbstractCeramic foams are being used in numerous industrial applications such as high-temperature thermal insulation, hot gas particulate filters, molten metal filters, catalyst support, and cores in high-temperature structural panels. The growing usage ceramic foams stems from the favorable properties such as low density, low thermal conductivity, and from their thermal and chemical stability. Recently Gauckler and colleagues developed a new method to produce ceramic foams. This method involves introducing gas bubbles into highly concentrated colloidal suspensions. The foam structure is stabilized by the suspended particles which align at the liquid/gas interface. Following the foaming stage, the wet green foams are dried and sintered. We have found that when making large foam bodies (i.e., >100 mm), cracks formation during the drying stage became a major issue. Following the rational of Scherer and Brinker in the drying of gels, we propose a model that explains the cracks formation in the foams and suggest a different procedure for successful drying of this system. Our solution is based on the addition of miscible cosolvents with low volatility to the aqueous phase. In this paper, we present the effectivity of different cosolvents in solving the cracking problems of large objects.

下载地址:https://ceramics.onlinelibrary.wiley.com/doi/full/10.1111/j.1551-2916.2010.03948.x

 

文献信息2Oummadi S, Nait-Ali B, Alzina A, et al. Distribution of water in ceramic green bodies during drying [J]. Journal of the European Ceramic Society, 2019, 39(10): 3164–3172.

推荐理由:这篇文章详细研究了氧化铝陶瓷坯体在干燥过程中的变化,研究了随着干燥时间的不同,坯体的重量变化、干燥收缩,并用核磁共振(MRI)检测了各个干燥阶段坯体的水分分布。在干燥的第一个阶段,坯体的收缩基本完成,水分在坯体内是均匀分布的。在干燥的第二阶段,坯体的尺寸基本已不发生变化,水分在孔洞内以蒸发的方式排出,水分的分布存在浓度梯度。在最后阶段,剩余的水分会残留在颗粒之间。这篇文章对于我们理解坯体的干燥过程、避免干燥开裂具有很大的意义。

AbstractIn order to investigate drying mechanisms at different stages, the distribution of water within the ceramic green bodies at different scales has been examined. The experimental measurements, using a simple weighing technique and Magnetic Resonance Imaging (MRI), show that during the first stage of drying involving shrinkage the material is constituted of uniquely solid and water with no gradient in water content within the sample. Then, during the second stage of drying, significant differences of water content as a function of position appear. As a complement, at the grain scale, observations using environmental scanning electron microscopy were made giving useful information on the solid–liquid–gas interfaces in the near surface part of the green body. Finally, the gradients in the water distribution were exploited to make a simple estimate of the diffusion coefficient of water with its dependence on the moisture content.

下载地址:http://www.sciencedirect.com/science/article/pii/S0955221919302298

 


本网站由阿里云提供云计算及安全服务 Powered by CloudDream