(中南大學 材料科學與工程學院,長沙 410083)
摘 要: 在氮氣保護下由鉬電阻爐中加熱(1 550~1 580 ℃)制得Y-Al-Si-O-N-F氧氟氮基礎玻璃。采用差示掃描量熱法(DSC)測定玻璃的玻璃轉變溫度(tg)和析晶峰溫度(tc)。利用XRD結合能譜分析(EDS)鑒定氧氟氮微晶玻璃中的物相,采用掃描電子顯微鏡(SEM)觀察微晶玻璃樣品的微觀形貌。結果表明:F含量的增加降低玻璃的tg和tc,并影響微晶玻璃的微觀結構以及晶體的尺寸和形貌;N含量的增加對析出晶相和微觀結構產(chǎn)生較大影響;基礎玻璃樣品熱處理后析出的主晶相為Y2Si2O7,次晶相隨N含量的提高由莫來石(Al6Si2O13)轉變成Si3Al6O12N2。與基礎玻璃相比,微晶玻璃的顯微硬度和抗彎強度有一定程度的提高。
關鍵字: Y-Al-Si-O-N-F;微晶玻璃;熱處理;顯微結構;力學性能
(School of Materials Science and Engineering, Central South University, Changsha 410083, China)
Abstract:Y-Al-Si-O-N-F oxyfluoronitride glasses were prepared by melting batches at 1 550-1 580 ℃ under N2 atmosphere in a Si-Mo-heated resistance furnace. Differential scanning calorimeter (DSC) was used to determine the glass transition temperature (tg) and crystallization temperature (tc). Crystalline phases in the oxyfluoronitride glass-ceramics were identified by X-ray diffractometry (XRD) and energy dispersion spectrometry (EDS). The microstructures of the glass-ceramics were observed by scanning electron microscopy (SEM). The results show that the addition of fluorine lowers the tg and tc of oxyfluoronitride glasses and affects the microstructures, including crystal size and morphology. Nitrogen affects the crystallization phases and microstructures. Y2Si2O7 appears as the major crystalline phase in all glass-ceramics obtained after heat treatment, and an increase in nitrogen content favors the formation of Si3Al6O12N2 rather than mullite (Al6Si2O13). The glass-ceramics exhibit higher microhardness and bending strength compared with the corresponding glasses with different fluorine or nitrogen contents.
Key words: Y-Al-Si-O-N-F; glass-ceramics; heat treatment; microstructure; mechanical properties


