摘要
以P2O5 和 ZrO2 为复合成核剂，Sb2O3为澄清剂，通过传统熔体冷却法制得掺稀土La2O3的SiO2-Li2O-K2O- B2O3系统基础玻璃。利用DSC、XRD、SEM和力学性能测试等方法研究La2O3含量对玻璃析晶行为、析出晶相种类及微晶玻璃力学性能的影响。结果表明：La2O3含量对基础玻璃的第一析晶峰对应的温度影响较大，对第二析晶峰对应的温度影响不明显；当La2O3的含量小于0.40%（摩尔分数）时，La2O3的引入不改变微晶玻璃主晶相类型；当La2O3含量增加到0.80%时，La2O3直接参与晶相组成，析出LaPO4晶相；同时，La2O3的引入提高了二硅酸锂晶相的析出温度；当La2O3含量为0.40%时，微晶玻璃的抗弯强度和弹性模量达到最高值，分别为328 MPa和143 GPa；当La2O3含量小于0.40%和大于1.20%时，微晶玻璃的断裂韧性随La2O3的增加变化较小；当La2O3含量为0.40%~1.20%时，微晶玻璃的断裂韧性随La2O3含量的增加而大幅度增加，最大断裂韧性达到3.34 MPa·m1/2。
The SiO2-Li2O-K2O-B2O3 glasses doping La2O3 were prepared by traditional melting quenching method, using P2O5 and ZrO2 as complex nucleating agent and Sb2O3 as clarifying agent. The effects of La2O3 content on the crystallization behavior, the crystalline phase and the mechanical properties of the glass-ceramics were investigated by using of DSC, XRD, SEM and mechanical property tester. The results show that, the change of La2O3 content mainly influences the exothermic peak temperature rather than the second exothermic peak temperature. When La2O3 content is lower than 0.40% （mole fraction）, the doping content of La2O3 does not change the main crystal phase type in the glass-ceramics. However, when the La2O3 content increases to 0.80%, the La2O3 directly involves in the lattice construction of LaPO4 micro-crystals. At the same time, La2O3 doping increases the precipitation temperature of Li2Si2O5 phase. When the La2O3 content is 0.40%, the glass-ceramics has the highest bending strength and elastic modulus, which are 328 MPa and 143 GPa, respectively. When La2O3 content is lower than 0.40% and higher than 1.20%, the fracture toughness of the glass-ceramics changes slightly with increasing La2O3 content. However, when La2O3 content is 0.40%？1.20%, the fracture toughness increases obviously with increasing La2O3 content, the biggest fracture toughness of the glass-ceramics reaches up to 3.34 MPa·m1/2.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2009年第11期2018-2023,共6页
The Chinese Journal of Nonferrous Metals
基金
国防军工新材料资助项目(JPPT-115-329)
关键词
氧化镧
二硅酸锂
微晶玻璃
力学性能
La2O3
lithium disilicate
glass-ceramics
mechanical properties
