Permeability Enhancement in Porous-Sintered Reaction-Bonded Silicon Nitrides

Abstract

Pressure drop across filter materials is critical for the effective performance of various kinds of filtering system. To evaluate the feasibility of lowering the pressure drop of porous sintered reaction-bonded silicon nitrides, permeability tests were conducted for specimens with different porosity and pore structure. The results showed that pore former size is a minor factor, while permeability (k) had a strong dependency on the amount of pore former. Prolonged sintering time (2 h vs 10 h at 17001C) increased the permeability by increasing the effective pore diameter, which compensates for the observed decrease in total porosity.

Reaction bonded silicon nitride foams: The influence of iron disilicide on microstructure and mechanical strength

“…This newly developed and near net-shape fabrication procedure is capable of producing RBSN foams which benefit from controlled and high levels of porosity (between 41 vol% and 87 vol%), pore interconnectivity, ease of fabrication, and low production cost. It must be mentioned that there are only a few studies on the fabrication and characterization of RBSN foams [8][9][10][11]. The RBSN foams in these studies have been produced based on dry-processing techniques such as uniaxial pressing resulting in closed-cell structures with low levels of porosity (maximum porosity o60 vol%).…”

Porous Si3N4 Ceramics Prepared via Nitridation of Si Powder with Si3N4 Filler and Postsintering

“…13 Before the 1980s, the studies were mainly centered on the formation of single-phase Si 3 N 4 without additives, and the role of H 2 on removal of surface silica and its effect on the nitridation were investigate. 14À17 Nowadays, some researches were investigated on postsintering behavior with different additives, such as Y 2 O 3 -MgO, 18 20 Si 3 N 4 as a filler has also been discussed in the nitridation of Si powder. [21][22][23] Si 3 N 4 filler not only contributes to the maintenance of an open pore network throughout the nitridation process but also provides a method of controlled reduction of the final density, especially to fabricate thick products.…”

Macroporous polyacrylates from terpene–acrylate thermoreversible photopolymerizable vehicle

“…Permeability of the porous material depends on both the volume fraction porosity and the pore size, often described with the Kozeny-Carmen model [17]. Permeability measurements were performed using a customized device through measurements of air flow and the difference in pressures.…”