Contact Resistance Modeling And Life Prediction Of Sealed Relay Under Storage Environment

Sealed relay is widely used in the field of aerospace.The entire life cycle of such products includes storage,transportation,working and other states,where the storage time is much longer than the working time.Therefore,it is necessary to ensure that the relay still maintains perfect performance after long-term storage time.The contact resistance between the contacts beyond the standard is the most important failure form of the sealed relays in the storage process and the relevant researches have aroused widespread concern.Around the core of the performance chances of the sealed relay during the storage process,the contact resistance was taken as the starting point.The resistance model and storage life prediction were studied in this paper.Firstly,the internal structure of the sealed relay was introduced.The samples were subjected to a storage life accelerated test and the movement of the relay contacts was taken to analyze the contact motion.Secondly,on the basis of studying the changes of the surface morphology of the contact surfaces,the concept of the difference-plane was proposed to restore the contact surface when the dynamic contact and static contact were in contact.The contact resistance model of the contact surface was established by calculating the wear amount of the contact surface morphology before and after the test and analyzing the morphological and compositional changes of the contact surface.Finally,the contact resistance was used as the key parameter to predict the storage life of the relay and the other performance parameters of the relay contact were combined.The distribution type of the pseudo life was checked to verify the reliability of the prediction method.On this basis,the storage life of the sealed relay under normal storage environment was predicted.This paper provides a necessary research basis and means for the development of contact resistance modeling and life prediction of sealed relays during storage process.The key technologies and related methods can also be applied to the performance study of other electromechanical components during storage process.