Selection And Tribological Analysis Of Electrical Contact Material In Starborne High Frequency Double-channel Rotating Joint

The use of the space rotating joint can greatly simplify the design scheme of the whole statellite,and the design of the required frequency band needs to adopt the contact design scheme,which will face the problem of the selection of space electrical contact materials.Reasonable selection of electrical contact materials can not only improve the reliability of electrical contact in the use of rotating joints,but also ensure the service life of rotating joints,so that it can reduce the wear rate of materials on the premise of meeting the electrical performance index.Reduce the generation of wear debris and prolong the service life of the joint.Foreign embargoes on this kind of joint,domestic research on this kind of joint is still blank,the research and development of this kind of joint is of great practical significance for the domestic corresponding frequency band research and development and even the future satellite networking.The specific studies are as follows:Firstly,based on the basic principles of electrical contact theory and tribological theory,the friction pairs composed of three kinds of space electrical contact materials are selected,including composite copper-based molybdenum disulfide prepared by powder metallurgy process.Silver alloy coated with silver film prepared by physical vapor deposition process,and gold alloy and gold-silver-copper alloy with rare and precious metals as the main components,these three kinds of materials are machined to form devices of corresponding sizes in the rotating joint.The friction life experiment was carried out by loading rotating joints respectively.Secondly,according to the relevant experimental conditions,the corresponding rotating mechanism is designed,the optimal rotating speed of the mechanism is set without affecting the friction performance of the material,and the electrical performance of the rotating joint is monitored in real time.The reliability of electrical contact and the friction life of electrcal contact materials are judged by detecting the phase runout of rotating joints.Finally,through the measurement of the surface of the material after the friction experient and the loss of the material quality before and after friction,a group of friction pair materials-gold alloy and gold-silver-copper alloy,which have high reliability of electrical contact,are selected to meet the requirements of the project.With the advantages of long friction life and less wear debris,it can fully meet the electrical performance and life requirements under space conditions.At the same time,according to the relevant experimental results,the reason why this material can meet the needs of the project can be explained from the point of view of tribology theory.