Study On The Synergistic Effect Of Surface Texture And Magnetic Nanofluids On The Tribological Properties Of 30CrMo3A

Gear pair is in the state of mixed lubrication or boundary lubrication for a long time,especially in the special conditions such as low speed and heavy load,the lack of lubricant between the contact surfaces often causes excessive wear of the tooth surface.Moreover,gear is prone to pitting,wear and gluing in the long-term friction process.Once the gear is damaged,it will cause great safety hazard to the whole mechanical system and operators.Therefore,how to design specific gear surface structure in gear meshing contact area,and precisely locate lubricating oil on the surface of gear meshing contact pair,so as to achieve lasting lubrication,in order to meet the lubrication requirements of gear under different environments,is a new problem faced by scientific researchers.In order to reduce tooth surface friction and improve tooth surface lubrication,the synergistic effects of bionic micro-texture technology and magnetic nanofluid technology on tribological properties of gear alloys were studied in this paper.The main research contents are as follows:(1)According to the radial ridge structure,crescent structure and waxy crystal structure of Nepenthes,bionic groove texture,crescent texture and circular texture were constructed respectively.A simplified model of gear with different bionic textures was established,and the influence of three different bionic textures on gear strength was analyzed by statics simulation.At the same time,the fluid domain unit model of biomimetic texture was constructed and the dynamic pressure effect of texture fluid was studied by fluid simulation.(2)The effects of laser scanning speed,laser power and pulse repetition rate on texture size were investigated by single factor experiment,and the optimal laser parameters were obtained.The above three types of bionic texture were machined on the surface of gear alloy with optimized laser parameters,and the friction and wear properties were studied by ball-disk friction and wear testing machine.The mechanism of friction and wear was revealed based on the morphology of wear chips,worn surface and the distribution of elements on worn surface.(3)The bionic circular texture was selected as the research object to explore the friction and wear properties of the texture in collaboration with magnetic nanofluids under low speed and light load,medium load and heavy load.By comparing and analyzing the friction coefficient,wear rate and wear morphology of gear alloys under single action of texture,single action of magnetic nanofluid,and synergistic action of texture and magnetic nanofluid,the synergistic antifriction mechanism of surface texture and magnetic nanofluid was revealed.(4)The experimental platform of ball-disk friction and wear was built,and the temperature control equipment was coupled.The tribological properties of texture-coupled magnetic nanofluids at different temperatures under oil-rich conditions were studied using this experimental platform.The wear mechanism of the texture-coupled magnetic nanofluids at different temperatures was analyzed based on the wear spot diameter,wear surface morphology and element content of the wear pair.In view of the problem that the absence of lubricant is more likely to cause excessive wear of friction pairs under high temperature conditions,this section further explores the friction and wear properties of texture-coordinated magnetic nanofluids under high temperature and starved lubricating conditions,and reveals the wear mechanism through the analysis of wear surface morphology.