Research On Mechanical Effects And Anti-cavitation Mechanism Of 2A70 Alloy By Cavitation Bubbles Induced By Laser Processing

The cavitation phenomenon is prevalent in the field of fluid machinery,Generally,the high velocity movement of the component in the liquid causes the formation of low pressure at the region that near the component,resulting in a pressure gradient,forming a vacuolization phenomenon.Shock waves and water jets have an influence on the stress of the mechanical mechanism in the period of the bubble pulse cycle.With the deep research of cavitation,academics began to explore the mechanical effect of bubble pulsation period as a aggrandizement method.As an advanced technology,laser induced cavitation becomes more and more important because of the maneuverability and the spherical symmetry of the cavitation bubble.In this paper,laser induced cavitation is used as the main method,through experimental exploration of laser energy change and superposition on the mechanical properties of 2A70 aluminum alloy of the modification effect.The specific effect of laser-induced cavitation strengthening material performance and prolonging the service life was demonstrated.Because the cavitation phenomenon occurs in the liquid environment and cavitation and chemical effects are mutual influence in the natural environment.In this paper,the anti cavitation performance of laser induced cavitation enhancement in marine environment was studied and studied by studying the mechanical properties the cavitation strengthened in 3.5% NaCl solution.The research contents and achievements are as follows:(1)Firstly,based on the hydrodynamic equation,the kinetic equations such as inertial growth,collapse and springback of the hollow cavities are discussed,and the mechanism of initiation and development of laser-induced cavitation is analyzed.Taking the 2A70 aluminum alloy as the experimental object,the effect of laser induced vacuolar effect and the pulsation impact and jet of cavitation on the surface of the material were studied,and the influence of the stress mechanism and thermodynamics were analyzed.(2)Secondly,a laser-induced cavitation experimental platform was set up,and the effect of laser incidence angle on the experimental target under the same energy and experimental conditions was studied.Mainly to contrast the laser cavitation of the enhanced range and depth of influence to determine the laser incidence angle.The variation law of the roughness,the residual stress and the hardness of the material with different laser energy intensity and repeated influence times were obtained,which proved the feasibility of the new technology that using laser induced cavitation to strengthen.The repeated multiple cavitation enhancement was compared to the group cavitation effect for characterizing the effect of material strengthening under the action of similar group cavitation,which provided experimental reference and mechanism for the application and popularization of the multiple effects of group vacuoles.(3)Thirdly,Considering the practical application environment of cavitation,the cavitation erosion effect of 2A70 aluminum alloy was obtained by cavitation experiment that use deionized water and 3.5% NaCl solution and the mechanical properties after cavitation are analyzed.The mutual influence between cavitation and chemical action was obtained.The specific parameters(hardness,residual stress and microstructure)of the experiment were obtained by ultrasonic cavitation test in different solution environments before and after laser induced cavitation strengthening.The specific effect of laser cavitation technique on cavitation resistance was obtained.The specific parameters of the anti-cavitation experiment in deionized water and 3.5% NaCl solution were compared with the same laser strengthening effect.The effect of laser strengthening on the cavitation erosion resistance of materials in different liquid environment was demonstrated,the modification law of laser cavitation on material was obtained.