The Design Of Metal-Glass Sealing Process Of Electrical Connector In Aerospace System And Investigation Of Microstructure Of Materials

Glass sealed electrical connectors has good mechanical strength, good heat durability, as well as good electrical parameters, which makes it used as high-reliability aerospace systems connector in high-pressure, high temperature and high stress situations.In order to increase the capability of independent innovation of domestic glass sealing technology, shorten the gap with that of developed countries, and to meet the need of a high insulation resistance, low leakage rate, high temperature durability and other characteristics of electrical connectors demands in war and space industry, manufacturers are actively increasing the investment in the research of the high level glass sealing connector. In this paper, we will provide the HuaFeng chemical plant in Fushun with production process design, production equipment, test and measurement equipment selection, optimization of basic test parameters, analysis of microscopic structures of metal-glass sealing materials for electrical connectors used in aerospace systems and strategic/tactical weapons. We will provide practical process, equipment and advanced technological path for small-scale practical production and reliable data for the technical parameters-microstructure-performance relationship.In this paper, we use process design and pilot study to develop the reasonable technology of vacuum purification, low vacuum pre-oxidation, control of the cooling rate after the heat sealing process for Kovar alloy, tests show that electrical connectors sealed with such technology can meet or exceed the performance required for aerospace systems; experiment shows that:in lower vacuum (10Pa), a pre-oxidation treatment to the Kovar alloy 4J29 connector shell and pin will generated more Fe3O4 and FeO oxide film, also a certain amount of Fe2O3 phase, the oxide film is conducive to fully integrate with the liquid vitreous, forming a high hermetic sealing; in a moderate controllable cooling rate (100℃/h), there will be a small amount of pores not less than 50 microns in the sealed glass, at the same time a small amount of small particles, uniformly distributed SiO2 crystalline phase, which ensure that the residual gas in the glass easy to discharge, not to leave large pores, and also inhibit crystallization of the vitreous and sub-phase, such pores and SiO2 crystallization has no adverse affect on the performance of connector.