TY - JOUR
T1 - Structure and performance control of porous Si3N4 ceramics fabricated by freeze-drying process
AU - Sun, Mengyong
AU - Yang, Shuangyan
AU - Gao, Xiaoju
AU - Man, Peng
AU - Qu, Junfeng
AU - Zhang, Wu
AU - Yin, Shaoqing
AU - Cheng, Laifei
N1 - Publisher Copyright:
© 2020
PY - 2021/3/15
Y1 - 2021/3/15
N2 - Effects of glycerin and silica sol on the structure and performance of porous Si3N4 ceramics that were prepared via freeze-drying were studied. Adding glycerol affected growth process of ice crystals, changed pore structural from bimodal peaks to triple peaks distribution, and formed regular honeycomb structure. This improved mechanical properties and electromagnetic wave transmission properties of Si3N4 ceramics. Therefore, adding glycerol changed mesoscopic morphology of the material. For porous Si3N4 ceramics with 72.5% porosity, flexural strength was 38 MPa, compressive strength was 42.6 MPa, and dielectric constant was 1.75 in the frequency range of 12.4–18 Hz as the amount of added glycerol increasing to 5 wt%. By reducing the sintering eutectic point of the system, the addition of silica sol promoted sintering shrinkage and formed new phases. Thus, pore size distribution was changed from bimodal to unimodal. Moreover, dielectric constant of samples increased from 2.25 to 3.5. Finally, structure and performance of porous Si3N4 ceramics were controlled via addition of glycerol and silica sol.
AB - Effects of glycerin and silica sol on the structure and performance of porous Si3N4 ceramics that were prepared via freeze-drying were studied. Adding glycerol affected growth process of ice crystals, changed pore structural from bimodal peaks to triple peaks distribution, and formed regular honeycomb structure. This improved mechanical properties and electromagnetic wave transmission properties of Si3N4 ceramics. Therefore, adding glycerol changed mesoscopic morphology of the material. For porous Si3N4 ceramics with 72.5% porosity, flexural strength was 38 MPa, compressive strength was 42.6 MPa, and dielectric constant was 1.75 in the frequency range of 12.4–18 Hz as the amount of added glycerol increasing to 5 wt%. By reducing the sintering eutectic point of the system, the addition of silica sol promoted sintering shrinkage and formed new phases. Thus, pore size distribution was changed from bimodal to unimodal. Moreover, dielectric constant of samples increased from 2.25 to 3.5. Finally, structure and performance of porous Si3N4 ceramics were controlled via addition of glycerol and silica sol.
KW - Freeze-drying
KW - Pore size distribution
KW - SiN ceramic
KW - Structure and performance control
UR - http://www.scopus.com/inward/record.url?scp=85097101488&partnerID=8YFLogxK
U2 - 10.1016/j.ceramint.2020.11.174
DO - 10.1016/j.ceramint.2020.11.174
M3 - 文章
AN - SCOPUS:85097101488
SN - 0272-8842
VL - 47
SP - 8169
EP - 8174
JO - Ceramics International
JF - Ceramics International
IS - 6
ER -