Friction Properties Of Impregnated Carbon Graphite Sealing Material In Vaccum Conditions

Mechanical seal is famous for good sealing performance, low leakage and otheradvantages, so it has been widely used in various fields. The frictional properties ofsealing materials under dry friction have a great impact in the sealing performanceand decide the service life of mechanical seal, it is necessary to do research on thefriction properties. Foreign and domestic scholars have studied dry frictionproperties of mechanical seals at atmospheric pressure, while little has been studiedunder high vacuum condition. View of this, this paper does the following work:With the help of test rig, this paper has shows the built of a mechanical sealfriction test system, including the design of test rig, in use of this test rig, this testsystem simulates grinding between mechanical seal pairs, tests the frictionproperties of impregnated carbon graphite mechanical seal materials under vacuumcondition. After tests, SEM is used to analyze the friction and wear mechanisms.In this paper the friction performance of seal material impregnated carbongraphite has been studied. The results show that the friction coefficient ofimpregnated alloy carbon graphite M120B, impregnated epoxy carbon graphiteM120H, impregnated antimony carbon graphite M120D, impregnated resin carbongraphite M120K and carbide YG6pairs increase with the increase of the speed,decrease with the increase of load and the reduction of vacuum, change little with invarious temperature. The friction coefficient of M120and YG6pairs in atmosphereis greater than in high vacuum. SEM is used to observe the surface of the specimenafter wear in high vacuum, the SEM analysis shows that the wear surface of M120Bis the most smooth, the wear surface of M120D has plastic deformation and form asurface film structure, most of it shows adhesive wear, the wear of M120is moreserious, some material has been torn, the main wear of M120H is adhesive, the mainwear of M120K is abrasive wear, forming a surface film structure, there are deepfurrows in the surface.All in all, the friction coefficient of M120K becomes large below20℃, it’s notsit for environment of high vacuum and low temperature. Under different conditionsthe friction coefficient of M120B is the smallest, it provides a reference for thechoice of high vacuum mechanical sealing material.