Current Research on the Sealing Performance of K9 Glass and Aviation Organic Glass Materials

Borosilicate glass （K9 optical glass） and polymethyl methacrylate （aviation organic glass, PMMA） are core transparent materials in aerospace, optical instruments and sealed cabin applications. Their service scenarios often involve complex working conditions such as dynamic loads, alternating temperature-humidity cycles, and drastic pressure changes. Significant differences exist between the two materials in key performance parameters, including thermal expansion coefficient, elastic modulus, surface energy and environmental adaptability, which directly affect the long-term reliability and stability of sealing interfaces. In this study, a systematically designed experimental scheme was adopted to compare the static sealing performance and interfacial durability of the two materials under standardized environmental conditions. The helium leakage rate was accurately quantified, and the correlation mechanism between material microstructures and macroscopic sealing performance was thoroughly analyzed. This work aims to provide solid experimental data support and theoretical references for material selection, process optimization and reliability design of sealing structures in aerospace, precision instruments and other fields.