Study On The Synergistic Effect Of Nano Magnetic Fluid And Surface Texture On The Tribological Properties Of Titanium Alloy

TC4 titanium alloy has a series of advantages such as light weight,high strength and excellent mechanical properties.It is widely used in various mechanical industries.However,titanium alloy has some disadvantages,such as high friction coefficient,unstable friction coefficient,serious adhesion and wear,which reduces its service life.Due to its unique lubrication mechanism,nano magnetic fluid can realize fixed-point lubrication under the action of magnetic field,so as to reduce the leakage of lubricating oil and the amount of lubricating oil and improve the lubrication efficiency.The reasonable arrangement of surface texture can reduce the friction coefficient and improve the wear resistance of materials.Therefore,this paper will focus on improving the lubrication performance of lubricating oil and enhancing the wear resistance of friction pair.Taking nano magnetic fluid as lubricant,oil storage and oil collection are carried out through surface texture.At the same time,nano magnetic fluid is adsorbed around the friction pair by magnetic field,and the improvement of tribological properties of TC4 titanium alloy under the synergistic action of the two is studied.Firstly,the influence mechanism of the polarity of nano magnetic fluid on the tribological properties was explored on different surface energy specimens.The surface texture of pits with different spacing is processed on the surface of titanium alloy by nano laser processor to increase the surface energy and form specimens with different surface energy.By comparing the changes of tribological properties of nano magnetic fluids with different polarity relative to the base carrier fluid,the influence mechanism of magnetic nanoparticles with different polarity on the friction and wear of titanium alloys with different surface energy was revealed.Secondly,the effect mechanism of external magnetic field on the tribological properties of nano magnetic fluids with different concentrations was studied.Firstly,the effect of nano magnetic fluid with different concentration on the friction and wear characteristics of titanium alloy was studied under different magnetic field intensity.Then,the concentration of nano magnetic fluid with the best tribological performance is selected to study the variation law of its average friction coefficient under variable load and variable speed.Finally,change the magnetization direction of the permanent magnet to explore the influence mechanism of different magnetic field directions on the tribological properties of nano magnetic fluid.Then,the influence of laser processing parameters on the texture morphology of grooved surface is studied.The effects of laser processing times,scanning speed,processing power and pulse frequency on texture processing depth and surface morphology were studied by single factor analysis.The relationship between laser processing parameters and surface texture forming effect is established,which lays a foundation for optimizing the friction and wear experiment of grooved surface texture.Finally,the effect of size parameters of surface texture on tribological properties was studied under nano magnetic fluid lubrication.Firstly,the influence of groove spacing on friction and wear performance is analyzed.After the optimal distribution spacing is tested,the depth and contour shape of the groove are changed by changing the laser scanning speed.At the same time,the width of the groove is changed by cutting to optimize the texture with the best tribological properties.For the texture with the best tribological properties,the effects of experimental sliding speed,loading load and applied magnetic field strength on its antifriction properties were studied.