通过化学法结合固相烧结技术制备了钛酸锌陶瓷, 掺杂V2O5和B2O3降低了陶瓷的烧结温度, 研究了V2O5-B2O3掺杂钛酸锌陶瓷的低温烧结行为、降温机制、相转变机制以及晶粒生长动力学特性. 结果表明, V2O5-B2O3掺杂有效地将钛酸锌陶瓷烧结温度从1100℃降至900℃以下; V2O5-B2O3复合掺杂缩小了六方相分解的温度区间; 高V2O5含量的复合掺杂试样中, 产生了异常长大的晶粒, 随B2O3加入量增加, 晶粒趋于均匀一致; 采用TPRE(Tradition Phenomenological Rate Equation)描述晶粒生长机制, 计算得晶粒生长激活能为315.5kJ/mol, 晶粒生长表达式为: G=K0[texp(-315.5×103/RT)]1/7.
Zinc titanate ceramics were prepared by the conventional mixed-oxide method combined with a chemical processing. The effects of V2O5-B2O3 additives on the
low-temperature sintering behavior and phase structures of zinc titanate ceramics were investigated; and phase transition mechanism and grain growth kinetics were discussed. The results show that the densification temperature of zinc titanate ceramics can be reduced from 1100 to below 900℃ by V2O5-B2O3 addition. The temperature of complete phase transition from hexagonal ZnTiO3 phase to cubic Zn2TiO4 is lowered from 945 to 930℃ for V2O5-B2O3 co-doped samples. Exaggerated grain growth found is in V-rich region in high-V content samples and disappeared with B2O3 content increasing, at the same time, the grains become uniform. V2O5-B2O3 additive increases the diffusion rate of structure unit and accelerates grains growth. The Tradition Phenomenological Rate Equation (TPRE) model is well fit for characterizing the grain growth kinetics of V2O5-B2O3 co-doped zinc titanate ceramics. According to TPRE, the grain growth activation energy calculated is 315.5kJ/mol, the grain growth expression is shown as G=K0[texp(-315.5×103/RT)]1/7. The Q value decreases for V0-doped zinc metatitanate-based ceramics in microwave region as compared to single-phase hexagonal ZnTiO3 ceramics. The value of dielectric constant depends on the amount of rutile phase from the decomposition of hexagonal ZnTiO3 phase and the bulk density of ceramics.
1 Kim H T, Hwang J C, NAM J H, et al. J Mater Res., 2003, 18 (5): 1067-1072.
2 Kim H T, Lanagan M T. J Am Ceram Soc., 2003, 86 (11): 1874-1878.
3 Kim H T, Byun J D, Kim Y H. Mater. Res. Bull., 1998, 33 (6) Part 1: 963-973.
4 Kim H T, Byun J D, Kim Y H. Mater. Res. Bull., 1998, 33 (6) Part 2: 975-986.
5 Golovchansk A, Kim H T, Kim Y H. J. Koren Phys. Soc., 1998, 32 (2): S1167-S1169.
6 Kim H T, Kim S H, Nahm S. J. Am. Ceram. Soc., 1999, 82 (11): 3043-3048.
7 Dulin F H, Rase D E. J. Am. Ceram. Soc., 1960, 43 (3): 125-131.
8 Yang J, Swisher J H. Materials Characterization., 1996, 37: 153-159.
9 候育冬. 博士学位论文. 西安: 西北工业大学, 2002.
10 Baldo J B, Bradt R R. J. Am. Ceram., 1988, 71 (9): 720-725.
11 Hillert M. Acta metall., 1965, 13 (3): 227-238.
12 肖明. 湖北大学学报(自然科学版), 2001, 23 (2): 134-138.
13 章天金, 周东祥, 姜胜林. 功能材料, 2000, 31 (5): 519-521.
