硅碱钙石微晶玻璃的析晶特性及其增韧机理研究

doi:10.15541/jim20150063

摘要/Abstract

摘要：

通过调整热处理工艺制备了不同结构的R₂O-CaO-SiO₂-F系硅碱钙石微晶玻璃, 分析了析晶特性和力学性能, 重点研究以硅碱钙石为主晶微晶玻璃的裂纹扩展机制及增韧机理。结果表明, 基础玻璃在低温处理时首先析出CaF₂微晶作为异质晶核, 一步法处理后得到岛屿状硬硅钙石/硅碱钙石复相微晶玻璃, 两步法处理后得到了力学性能优异、具有板条交错结构的硅碱钙石微晶玻璃。研究发现, 硅碱钙石微晶玻璃的裂纹扩展受到周围板条晶体取向及晶界影响, 存在穿晶断裂和沿晶断裂两种模式扩展, 呈现出随机取向的折线或台阶状裂纹路径。其中具有一定长径比的板条状硅碱钙石具有较好的桥联作用, 承载补强效果显著, 此外硅碱钙石晶体与玻璃相之间存在的残余应力, 有利于缓解裂纹应力集中以及增加裂纹扩展能。即, 硅碱钙石微晶玻璃优异的力学性能是各种增强和增韧机制综合作用的结果。

关键词: R2O-CaO-SiO2-F系微晶玻璃, 硅碱钙石, 裂纹扩展, 增韧机理

Abstract:

The R₂O-CaO-SiO₂-F system glass-ceramics were prepared through different heat treatment schedules. The crystallization, microstructure and mechanical properties, especially the crack propagation and toughening mechanism of the canasite-based glass-ceramics, were studied. The results show that CaF₂ crystallites precipitate firstly during heat treatment at low temperature. After one-step heat treatment block-like xonotlite/canasite complex phases can be obtained. And after two-step heat treatment, the canasite-based glass-ceramics, composed of particularly interlocking blade-like crystals, are obtained with excellent mechanical properties. The micrographs suggest the orientation and interface of canasite crystals radically change the crack propagation, showing intercrystalline and transcrystalline cracks forming random-step or fold-like line. Based on these results, the blade-like canasite crystals at certain slenderness ratios, display favorable anti-cracking effect because of their bridging toughen mechanism. In addition, the residual stress between matrix and crystals also benefits relaxation of stress and deflection of crack. So, the excellent mechanical properties of the as-prepared glass-ceramics are resulting from multiple toughening mechanisms.

Key words: R2O-CaO-SiO2-F glass-ceramics, canasite, crack propagation, toughening mechanism

中图分类号:

TQ174

李要辉, 王晋珍, 黄幼榕. 硅碱钙石微晶玻璃的析晶特性及其增韧机理研究[J]. 无机材料学报, 2015, 30(9): 977-983.

LI Yao-Hui, WANG Jin-Zhen, HUANG You-Rong. Characterization and Toughening Mechanism of Crystallization of Canasite Glass-ceramics[J]. Journal of Inorganic Materials, 2015, 30(9): 977-983.

图/表 11

图1 基础玻璃不同热处理制度曲线

Fig. 1 Diagram of the heat treatment schedule

图2 不同炉次基础玻璃的DSC曲线

Fig. 2 DSC curves of different RCSF casting glasses

图3 不同温度一步法热处理后样品的XRD图谱

Fig. 3 XRD patterns of glass-ceramics after one-step heat treatment

图4 不同温度两步法热处理后样品的XRD衍图谱

Fig. 4 XRD patterns of glass-ceramics after two-step heat treatment

图5 850℃(a)一步法和(b)两步法热处理后微晶玻璃的微观结构形貌

Fig. 5 SEM images of glass-ceramics after one-step (a) and two-step (b) heat treatment nsert is the enlarged image of the bladed morphology

表1 RCSF基础玻璃和微晶玻璃的力学性能数据表(GC: Glass-ceramics)

Table 1 Mechanical properties of the RCSF glass and glass-ceramics (GC)

Sample	Hardness, H/GPa	Modulus, E/GPa	Flexural/MPa	Impact toughness / (kJ·m^-2)	Fracture toughness /(MPa·m^1/2)
Casting glass	7.48±0.21	73.66±1.78	64~69	1.32	0.77±0.06
GC-one-step	7.32±0.05	77.12±1.13	83~97	2.56	1.17±0.06
GC-two-step	7.52±0.31	77.82±3.23	109~119	6.70	1.72±0.45

图6 RCSF基础玻璃的裂纹扩展形貌

Fig. 6 SEM images of crack propagation of RCSF casting glasses Insert shows the morphology of indentation

图7 一步法热处理的RCSF微晶玻璃的裂纹扩展形貌

Fig. 7 SEM images of crack propagation of RCSF glass- ceramics after one-step heat treatment sert shows the morphology of indentation

图8 两步法处理的RCSF硅碱钙石微晶玻璃的压痕SEM照片

Fig. 8 SEM images of indentation of RCSF canasite glass- ceramics after two-step heat treatment

图9 两步法处理的RCSF硅碱钙石微晶玻璃的裂纹扩展SEM照片

Fig. 9 SEM images of crack propagation of RCSF canasite glass-ceramics after two-step heat treatment

图10 RCSF玻璃析晶前后的热膨胀曲线

Fig. 10 Thermal expansion curves of casting glass and canasite glass-ceramics

参考文献 24

[1]	CHENG JINSHU, LI HONG, TANG LI YING, et al.Glassceramics. Chemical Industry Press, 2006.
[2]	HOLAND W, BEALL G H.Glass-ceramic Technology. The Ameriean Ceramie Society, Westerville, OH, 2002.
[3]	BEALL G H. Alkali Metal, Calcium Fluorosilicate Glass-ceramic Articles. US Patent No. 4386162, 1983.
[4]	BEALL G H.Chain silicate glass-ceramics.Journal of Non-Crystalline Solids, 1991, 129(1/2/3):163-173.
[5]	WANG SHUANGHUA, YANG ZHIFANG, YANG ZHI-HONG, et al.Preparation and machinable properties of the in-situ fluorcanasite micro glass-ceramic composite.Materials Review, 2007, 21(9): 96-99.
[6]	MILLER C A, KOKUBO T, REANEY I M, et al.Formation of apatite layers on modified canasite glass-ceramics in simulated body fluid.Journal of Biomedical Materials Research, 2002, 59(3): 473-480.
[7]	BARROS VMD, SALATA L A, SVERZUT C E, et al.In vivo bone tissue response to a canasite glass-ceramic.Biomaterials, 2002, 23(14): 2895-2900.
[8]	WANG CHUNHUA, YANG XIAOJUN.Study on the structure and properties of low-temperature glass-ceramic bond.Diamond & Abrasives Engineering, 2011, 2(31): 58-62.
[9]	KANCHANARAT N, Miller C A, HATTON P V, et al.Early stages of crystallization in canasite-based glass ceramics.Journal of the American Ceramic Society, 2005, 88(11): 3198-3204.
[10]	HILL R G, LAW R V,O’DONNELL M D, et al. Characterisation of fluorine containing glasses and glass-ceramics by 19F magic angle spinning nuclear magnetic resonance spectroscopy. Journal of the European Ceramic Society, 2009, 29(11): 2185-2191.
[11]	MIRSANEH M, REANEY I M, JAMES P F, et al.Effect of CaF2 and CaO substituted for MgO on the phase evolution and mechanical properties of K-Fluorrichterite glass ceramics.Journal of the American Ceramic Society, 2006, 89(2): 587-595.
[12]	JOHNSON A, SHAREEF M Y, VAN NOORT R, et al.Effect of furnace type and ceramming heat treatment conditions on the biaxial flexural strength of a canasite glass-ceramic.Dental Materials, 2000, 16(4): 280-284.
[13]	JOHNSON A, SHAREEF M Y, WALSH J M, et al.The effect of casting conditions on the biaxial flexural strength of glass-ceramic materials.Dental Materials, 1998, 14(6): 412-416.
[14]	SONG SHUXIN, ZHENG WEIHONG.Effect of CaO content on structure and crystallization of RCSF glass-ceramics.Journal of Wuhan University of Technology, 2009, 31(22): 23-26.
[15]	CHENG JINSHU, DENG WEI, ZHENG WEIHONG, et al.Effect of K2O content on crystallization of R2O-CaO-SiO2-F glass-ceramics.Journal of Wuhan University of Technology, 2010, 32(8): 26-29.
[16]	SONG SHUXIN, CHENG JINSHU, ZHENG WEIHONG, et al.Effect of mass fraction of Al2O3 on structure and crystallization of R2O-CaO-SiO2-F glass-ceramics.Glass & Ename, 2009, 37(4): 5-9.
[17]	ZHENG WEIHONG, YANG KUN.Effect of F on phase transition of R2O-CaO-SiO2 system glass-ceramics.Journal of Wuhan University of Technology, 2010, 32(22): 84-86.
[18]	DENG WEI, SONG SHUXIN.Effect of F content on structure and crystallization of RCSF glass-ceramics.Journal of Wuhan University of Technology, 2009, 31(22): 16-18.
[19]	ZHOU XIYA, HU JUN, ZHOU BINYANG, et al.Effect of fluorine content on crystallization of CaO-SiO2-R2O-F glass-ceramic.Bulletin of the Chinese Ceramic Society, 2009, 28(5): 168-172.
[20]	DENG WEI, GONG YUXUAN, CHENG JIN-SAU, et al.Liquid- phase separation and crystallization of high silicon canasite-based glass ceramic.Journal of Non-Crystalline Solids, 2014, 385: 47-54.
[21]	CHENG JINSHU, DENG WEI, ZHENG WEIHONG, et al.Phase transition of different crystals in canasite-based glass-ceramics.Journal of the Chinese Ceramic Society, 2012, 40(10): 1415-1420.
[22]	LI HONG, WU YANPING, CHEN FANGWEI, et al.Influence of Heat Treatment on crystallization properties of colored RCS glass-ceramics.Journal of the Chinese Ceramic Society, 2011, 39(1): 143-147.
[23]	YANG LANLAN, DENG ZHENLU, DENG WEI, et al.Influence of Co2O3 and K2Cr2O7 on colouring and crystallization of R2O-CaO-SiO2-F glass-ceramics.Journal of Wuhan University of Technology, 2010, 32(22): 32-35.
[24]	DENG WEI, CHENG JINSHU, TAN PEIJING, et al.Chemical durability and weathering resistance of canasite based glass and glass-ceramics.Journal of Non-Crystalline Solids, 2012, 358(21): 2847-2854.