(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083；
2. 中南大學(xué) 有色金屬材料科學(xué)與工程教育部重點(diǎn)實(shí)驗(yàn)室，長沙 410083)
摘 要: 以P2O5 和 ZrO2 為復(fù)合成核劑，Sb2O3為澄清劑，通過傳統(tǒng)熔體冷卻法制得摻稀土La2O3的SiO2-Li2O-K2O- B2O3系統(tǒng)基礎(chǔ)玻璃。利用DSC、XRD、SEM和力學(xué)性能測(cè)試等方法研究La2O3含量對(duì)玻璃析晶行為、析出晶相種類及微晶玻璃力學(xué)性能的影響。結(jié)果表明：La2O3含量對(duì)基礎(chǔ)玻璃的第一析晶峰對(duì)應(yīng)的溫度影響較大，對(duì)第二析晶峰對(duì)應(yīng)的溫度影響不明顯；當(dāng)La2O3的含量小于0.40%(摩爾分?jǐn)?shù))時(shí)，La2O3的引入不改變微晶玻璃主晶相類型；當(dāng)La2O3含量增加到0.80%時(shí)，La2O3直接參與晶相組成，析出LaPO4晶相；同時(shí)，La2O3的引入提高了二硅酸鋰晶相的析出溫度；當(dāng)La2O3含量為0.40%時(shí)，微晶玻璃的抗彎強(qiáng)度和彈性模量達(dá)到最高值，分別為328 MPa和143 GPa；當(dāng)La2O3含量小于0.40%和大于1.20%時(shí)，微晶玻璃的斷裂韌性隨La2O3的增加變化較小；當(dāng)La2O3含量為0.40%~1.20%時(shí)，微晶玻璃的斷裂韌性隨La2O3含量的增加而大幅度增加，最大斷裂韌性達(dá)到3.34 MPa·m1/2。
關(guān)鍵字: 氧化鑭；二硅酸鋰；微晶玻璃；力學(xué)性能
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Non-ferrous Metal Materials Science and Engineering, Ministry of Education,
Central South University, Changsha 410083, China）
Abstract: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.
Key words: La2O3; lithium disilicate; glass-ceramics; mechanical properties
