玻璃料对可陶瓷化硅橡胶基复合材料耐高温性能的影响

玻璃料可以改善可陶瓷化硅橡胶基复合材料高温热解后的力学强度，保持结构的完整性。为了研究玻璃料的成分对云母/硅橡胶复合材料耐高温性能的影响，分别以玻璃料A和B为助熔剂，制得了2种复合材料，研究了其力学性能、微观形貌、热分解性能及陶瓷化机制。结果表明:云母/硅橡胶复合材料常温拉伸强度为3~4 MPa，600~1 200℃下热解后试样的弯曲强度在0.3~4.5 MPa之间，且保持结构完整；SEM结果显示玻璃料B有助于形成大量的液相结构，更好地改善热解后形成的陶瓷层的强度和结构；TG结果显示玻璃料可以加速硅橡胶的分解，因此要控制玻璃料的加入量；XRD结果显示在温度变化过程中，添加含SiO₂和K₂O成分较多的玻璃料B至云母/硅橡胶复合材料中形成了非晶相和钾长石（K₂O·Al₂O₃·6SiO₂），从而提高陶瓷层的强度。 

Effect of glass frits on high-temperature resistance properties of ceramifiable silicone rubber matrix composites

Using glass frits can improve mechanical strength and keep structure integrity of ceramifiable silicone rubber matrix composites after pyrolysis at high temperature.In order to study the effects of composition of glass frits on the high-temperature resistance properties of muscovite/silicone rubber composites,two composites were prepared by using glass frits A and B as fluxing agent,respectively.The mechanical properties,microstructure, thermal decomposition properties and ceramic mechanism of both composites were studied.The results show that tensile strength of muscovite/silicone rubber composites is 3~4 MPa at room temperature,and flexural strength of the samples after pyrolysis is 0.3-4.5 MPa and can keep structure integrity at 600-1 200 ℃.SEM results reveal that glass frit B is helpful to form a large amount of liquid phase structure,and improve the strength and structure of ce-ramic layer produced after pyrolysis.TG results show that glass frits can accelerate the decomposition of silicone rubber,so the amount of glass frits should be controlled.XRD results show that adding glass frit B which includes more SiO2 and K2 O to muscovite/silicone rubber composites can form an amorphous phase and a potassium alumi-num silicate (K2 O·Al2 O3 ·6SiO2 )during the temperature change and therefore increase the strength of ceramic layer.