TY - JOUR
T1 - The effect of CaO-TiO2 on the sintering properties of SiC matrix composites
AU - Pan, Bo
AU - Li, Xiao Yun
AU - Qiu, Tai
AU - Yang, Jian
N1 - Publisher Copyright:
©, 2014, Journal of Functional Materials. All right reserved.
PY - 2014/11/15
Y1 - 2014/11/15
N2 - 6H-SiC and α-Al2O3 powders that as raw materials were mixed as mass ratio of 7:3 with CaO and TiO2 as sintering additives. The green body was preoxidated for 1 h at 1200℃ after being pressed. Sic matrix composites were prepared by pressureless sintering for 1 h in hydrogen atmosphere. The effects of CaO-TiO2 content and sintering temperature on the sintering properties and phasecomposition were investigated. The results suggested that: withthe increase of sintering temperature form 1400 to 1 500℃, the compactness improves significantly. At the sintering temperature of 1 450℃, the samples were basically compact. And the sample's apparent porosity decreased to 0.15% with m(CaO-TiO2) of 10% added. The reaction of CaO-TiO2 cristobalite, with α-Al2O3, had generated CaAl2Si2O8 at 1200℃, and generated CaTiSiO5 after 1 300℃, which promote the 6H-SiC further oxidation. In the process of sintering, CaAl2Si2O8 formed liquid glass phase which deposits mullite and promoted sample's densification. At 1 500℃, the main crystal phase of the composite material was 6H-SiC, mullite.
AB - 6H-SiC and α-Al2O3 powders that as raw materials were mixed as mass ratio of 7:3 with CaO and TiO2 as sintering additives. The green body was preoxidated for 1 h at 1200℃ after being pressed. Sic matrix composites were prepared by pressureless sintering for 1 h in hydrogen atmosphere. The effects of CaO-TiO2 content and sintering temperature on the sintering properties and phasecomposition were investigated. The results suggested that: withthe increase of sintering temperature form 1400 to 1 500℃, the compactness improves significantly. At the sintering temperature of 1 450℃, the samples were basically compact. And the sample's apparent porosity decreased to 0.15% with m(CaO-TiO2) of 10% added. The reaction of CaO-TiO2 cristobalite, with α-Al2O3, had generated CaAl2Si2O8 at 1200℃, and generated CaTiSiO5 after 1 300℃, which promote the 6H-SiC further oxidation. In the process of sintering, CaAl2Si2O8 formed liquid glass phase which deposits mullite and promoted sample's densification. At 1 500℃, the main crystal phase of the composite material was 6H-SiC, mullite.
KW - Apparent porosity
KW - Hydrogen
KW - Pressureless sintering
KW - SiC
UR - http://www.scopus.com/inward/record.url?scp=84920746886&partnerID=8YFLogxK
U2 - 10.3969/j.issn.1001-9731.2014.21.015
DO - 10.3969/j.issn.1001-9731.2014.21.015
M3 - 文章
AN - SCOPUS:84920746886
SN - 1001-9731
VL - 45
SP - 21068
EP - 21071
JO - Gongneng Cailiao/Journal of Functional Materials
JF - Gongneng Cailiao/Journal of Functional Materials
IS - 21
ER -