气悬浮技术制备铝酸钙玻璃及其性能研究

Preparation of calcium-aluminate glass by air suspension technology and its properties

铝酸钙玻璃是以Al2O_(3)和CaO为主要成分的红外光学玻璃,但因为其具有很强的析晶倾向,导致玻璃形成能力差,在一定程度上影响了该材料在红外成像制导系统、红外激光等光学领域的应用。通过添加微量网络形成体SiO_(2),可以提高玻璃的形成能力。本研究利用设备简便、可操作性强、对实验环境的要求较低和便于观察的气悬浮技术快速制备大量(1-x)CaAlO_(3)-xSiO_(2)玻璃微珠,选用4N7级SiO_(2)制备不同SiO_(2)摩尔分数的CaAlO_(3)-SiO_(2)玻璃,对其热学稳定性、晶相结构、微观结构、力学性能以及光学特性进行测试。实验结果表明:在SiO_(2)摩尔分数为10%,即CAS-2(90%CaAlO_(3)-10%SiO_(2))时,热稳定参数ΔT(ΔT=T_(c)-T_(g),T_(c)为玻璃的析晶温度,T_(g)为玻璃的玻璃化转变温度)最大(ΔT=435 K),玻璃形成能力最强,热稳定性最好。热处理后的CAS-2样品仍为玻璃相,证明了热处理未改变其晶相结构。CAS-2的平均维氏硬度值为639,力学性能相对较好。对样品进行的折射、透射和红外透射性能的光学测试结果也证实了该样品的光学特性良好。

Calcium-aluminate glass,with Al2O_(3) and CaO as its main components,is an infrared optical glass.However,it has a strong crystallization tendency,resulting in poor glass formtion ability which has to some extent affected its applications in the field of optics,such as infrared imaging guidance systems and infrared lasers.By adding trace amounts of network-forming agent SiO_(2),the glass-forming ability can be improved.A large amount of(1-x)CaAlO_(3)-xSiO_(2) glass microspheres were rapidly prepared using the air suspension technology due to its simplicity,high operability,low experimental environment requirements,and ease of observation.Glass composed of CaAlO_(3)-SiO_(2) with different SiO_(2) molar fractions were prepared using 4N7 grade SiO_(2),and their thermal stability,phase structure,microstructure,mechanical properties,and optical characteristics were tested.The experimental results showed that when the SiO_(2) molar fraction is 10%,i.e.,CAS-2(90%CaAlO_(3)-10%SiO_(2)),the thermal stability parameter ΔT(ΔT=T_(c)-T^(g),T_(c) is crystallization temperature of glass,T_(g) is glass transition temperature)is the largest(ΔT=435 K),indicating the strongest glass-forming ability and the best thermal stability.The heat-treated CAS-2 sample remained in the glass phase,demonstrating that the heat treatment did not alter its phase structure.CAS-2 exhibited an average Vickers hardness value of 639,indicating relatively good mechanical properties.Optical tests for refractive index,transmission,and infrared transparency also confirmed the excellent optical characteristics of this sample.