Effect of added TiO 2 on the mechanical properties of sintered Al 2 O 3 insulator

• Published in: 대한금속재료학회지 Vol. 61; no. 5; pp. 330 - 337
• Main Authors: 김리주, Ri Joo Kim, 정한결, Han Gyeol Jeong, 손예지, Ye Ji Son, 시소연, So Yeon Si, 류성수, Sung-soo Ryu, 고상기, Sang Ki Ko, 홍현선, Hyun Seon Hong
• Format: Journal Article
• Language: Korean
• Published: 대한금속재료학회 05.05.2023
• Subjects: Al 2</ sub>O 3</ sub> powder; densification; Insulator; Microstructure
• ISSN: 1738-8228

The effect of TiO 2 additive concentration and sintering temperatures on the densification of alumina (Al 2 O 3 ) ceramics were investigated. Densified alumina specimens were prepared by uniaxial pressing at a pressure of 60 MPa followed by isothermal heating at either 1400, 1500, or 1600 ℃ for 2 h. The relative density, microstructure, crystallinity, and hardness were investigated, and the correlation between properties and structure was discussed in relation to TiO 2 addition and sintering temperature. The densities of the 0.05wt%-TiO 2 specimens sintered at 1500 and 1600 ℃ had higher values than the pure alumina specimens. Adding more than 5.0wt% TiO 2 lowered the relative density. The maximum achieved density was 99.7% at 0.05wt% TiO 2 addition. Shrinkage and hardness analyses confirmed that the sintering temperature for the Al 2 O 3 insulator could be lowered by adding TiO 2 . The optimal concentration to obtain a dense alumina with high hardness for insulator use was determined to be in the range of 0.05 to 1.0 wt% of TiO 2 . These results provide fundamental composition and process optimization data for the development of high-dielectric alumina insulators. (Received 24 November, 2022; Accepted 1 Fabruary, 2023)