多孔氮化硅表面封孔防潮增强涂层的研究(英文)

Study on Damp-proof and Enhanced Coating on Porous Silicon Nitride Surface by Sealing

以Li2O-Al2O3-SiO2体系为基础,添加外加剂,采用溶胶-凝胶法在多孔氮化硅表面制备了封孔防潮涂层,采用扫描电子显微镜（SEM）观察了涂层的微观形貌;用阿基米德法测量了封孔前后基体的密度、吸水率和显气孔率:采用万能试验机测试了封孔前后材料的抗弯强度;用电弧加热器和毫米波矢量网络分析仪系统测试了在烧蚀条件下的透波性能。结果表明,封孔防潮处理使基体吸水率下降了93.73%至96.74%,,强度提高了8.21%15.56%,封孔后弧板样件的毫米波插入损耗在各频段变化都较小,表明材料在各波段均有良好的高温透波性能。

Damp-proof and enhanced coating was fabricated on the porous silicon nitride substrate by sol-gel method,with Li_2O-Al_2O_3-SiO_2 as the basic materials and other additives were added.The morphology of the coating was observed by scanning electron microscope(SEM).The density,water absorption and porosity of porous silicon nitride before and after sealing were tested by Archimedes method.The bending strength of the sample before and after sealing was tested by universal testing machine.The electrical transparent property under the condition of ablation was tested by electric arc heater and millimeter-wave vector network analyzer test system.The results indicate that the water absorption of porous silicon nitride decreases by 93.73%~96.74%,and the bending strength of porous silicon nitride was increases by 8.21%~15.56%.Millimeter-wave insertion loss of arc plate samples after sealing changes little at each frequency,which shows that the sample has good transparent property at high temperature.