Thermal properties of field‐assisted‐sintered SiCN–Y2O3 composites. Issue 2 (21st November 2022)

• Record Type: Journal Article
• Authors: Zhang, Zhao; Li, Quan; Maiti, Sanat Chandra; Shen, Xingchen; He, Jian; Peng, Fei; Bordia, Ranjendra K.
• Other Names: Fukushima Manabu guestEditor.; Wang Jingyang guestEditor.; Balaya Palani guestEditor.; Kim Young‐Wook guestEditor.; Singh Mrityunjay guestEditor.
• Is Part Of: International journal of applied ceramic technology. Volume 20:Issue 2(2023)
• Page Start: 1060
• Page End: 1070
• Publication Date: 2022-11-21
• Subjects: composites -- field‐assisted sintering technology (FAST) -- polymer precursor -- thermal properties; Ceramics -- Periodicals; Ceramics -- Technological innovations -- Periodicals; 620.1405
• DOI: 10.1111/ijac.14265
• Languages: English
• ISSNs: 1546-542X

Abstract

Abstract: Polymer‐derived amorphous SiCN has excellent high‐temperature stability and properties. To reduce the shrinkage during pyrolysis and to improve the high‐temperature oxidation resistance, Y2 O3 was added as a filler. In this study, polymer‐derived SiCN–Y2 O3 composites were fabricated by mixing a polymeric precursor of SiCN with Y2 O3 submicron powders in different ratios. The mixtures were cross‐linked and pyrolyzed in argon. SiCN–Y2 O3 composites were processed using field‐assisted sintering technology at 1350°C for 5 min under vacuum. Dense SiCN–Y2 O3 composite pellets were successfully made with relative density higher than 98% and homogeneous microstructure. Due to low temperature and short time of the heat‐treatment, the grain growth of Y2 O3 was substantially inhibited. The Y2 O3 grain size was ∼1 μm after sintering. The composites' heat capacity, thermal diffusivity, and thermal expansion coefficients were characterized as a function of temperature. The thermal conductivity of the composites ceramics decreased as the amount of amorphous SiCN increased and the coefficient of thermal expansion (CTE) of the composites increased with Y2 O3 content. However, the thermal conductivity and CTE did not follow the rule of mixture. This is likely due to the partial oxidation of SiCN and the resultant impurity phases such as Y2 SiO5, Y2 Si2 O7, and Y4.67 (SiO4 )3 O.