무가압 어닐드한 SiC-TiB2 전도성 복합체의 특성에 미치는 In Situ YAG의 영향 (Effects of In Situ YAG on Properties of the Pressurless Annealed SiC-TiB2 Electroconductive Ceramic Composites)

서지정보

· 발행기관 : 대한전기학회
· 수록지 정보 : 전기학회논문지ABCD / 57권 / 5호 / 808 ~ 815페이지
· 저자명 : 신용덕, 주진영, 고태헌

초록

The composites were fabricated 61[vol.%] β-SiC and 39[vol.%] TiB2 powders with the liquid forming additives of 8, 12, 16[wt%] Al2O3+Y2O3 as a sintering aid by pressureless annealing at 1650[℃] for 4 hours. The present study investigated the influence of the content of Al2O3+Y2O3 sintering additives on the microstructure, mechanical and electrical properties of the pressureless annealed SiC-TiB2 electroconductive ceramic composites. Reactions between SiC and transition metal TiB2 were not observed in the microstructure and the phase analysis of the pressureless annealed SiC-TiB2 electroconductive ceramic composites. Phase analysis of SiC-TiB2 composites by XRD revealed mostly of α-SiC(6H), β-SiC(3C), TiB2, and In Situ YAG(Al5Y3O12). The relative density of SiC-TiB2 composites was lowered due to gaseous products of the result of reaction between SiC and Al2O3+Y2O3. There is another reason which pressureless annealed temperature 1650[℃] is lower 300～450[℃] than applied pressure sintering temperature 1950～2100[℃]. The relative density, the flexural strength, the Young‘s modulus and the Vicker's hardness showed the highest value of 82.29[%], 189.5[Mpa], 54.60[Gpa] and 2.84[Gpa] for SiC-TiB2 composites added with 16[wt%] Al2O3+Y2O3 additives at room temperature. Abnormal grain growth takes place during phase transformation from β-SiC into α-SiC was correlated with In Situ YAG phase by reaction between Al2O3 and Y2O3 additive during sintering. The electrical resistivity showed the lowest value of 0.0117[Ωㆍ㎝] for 16[wt%] Al2O3+Y2O3 additives at 25[℃]. The electrical resistivity was all negative temperature coefficient resistance (NTCR) in the temperature ranges from 25℃ to 700[℃]. The resistance temperature coefficient of composite showed the lowest value of -2.310-3[℃]-1 for 16[wt%] additives in the temperature ranges from 25[℃] to 100[℃].

영어초록

The composites were fabricated 61[vol.%] β-SiC and 39[vol.%] TiB2 powders with the liquid forming additives of 8, 12, 16[wt%] Al2O3+Y2O3 as a sintering aid by pressureless annealing at 1650[℃] for 4 hours. The present study investigated the influence of the content of Al2O3+Y2O3 sintering additives on the microstructure, mechanical and electrical properties of the pressureless annealed SiC-TiB2 electroconductive ceramic composites. Reactions between SiC and transition metal TiB2 were not observed in the microstructure and the phase analysis of the pressureless annealed SiC-TiB2 electroconductive ceramic composites. Phase analysis of SiC-TiB2 composites by XRD revealed mostly of α-SiC(6H), β-SiC(3C), TiB2, and In Situ YAG(Al5Y3O12). The relative density of SiC-TiB2 composites was lowered due to gaseous products of the result of reaction between SiC and Al2O3+Y2O3. There is another reason which pressureless annealed temperature 1650[℃] is lower 300～450[℃] than applied pressure sintering temperature 1950～2100[℃]. The relative density, the flexural strength, the Young‘s modulus and the Vicker's hardness showed the highest value of 82.29[%], 189.5[Mpa], 54.60[Gpa] and 2.84[Gpa] for SiC-TiB2 composites added with 16[wt%] Al2O3+Y2O3 additives at room temperature. Abnormal grain growth takes place during phase transformation from β-SiC into α-SiC was correlated with In Situ YAG phase by reaction between Al2O3 and Y2O3 additive during sintering. The electrical resistivity showed the lowest value of 0.0117[Ωㆍ㎝] for 16[wt%] Al2O3+Y2O3 additives at 25[℃]. The electrical resistivity was all negative temperature coefficient resistance (NTCR) in the temperature ranges from 25℃ to 700[℃]. The resistance temperature coefficient of composite showed the lowest value of -2.310-3[℃]-1 for 16[wt%] additives in the temperature ranges from 25[℃] to 100[℃].

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