Heat Transfer Friction Properties And Processing Optimization Of Mixed Vegetable Oil-Based Coaxial Electrostatic Atomization Cutting

Compared with traditional MQL technology,coaxial electrostatic atomization has better cooling and lubrication performance,and is more environmentally friendly.In coaxial electrostatic atomization machining,the base oil of green lubricant is mainly plant cutting oil.Among vegetable oils,castor oil has the best lubrication performance.However,due to its low conductivity and high viscosity,it is difficult to achieve good lubrication performance by using pure castor oil as the external fluid of coaxial electrostatic atomization.Mixing with other vegetable oils can improve the electrical and flow properties of castor oil,improve the effect in coaxial electrostatic atomization,and promote the lubrication performance.Therefore,in order to comprehensively analyze the influence of mixed vegetable oil as an external fluid of coaxial electrostatic atomization on machining,the friction and heat transfer properties and machining properties of mixed vegetable oil in coaxial electrostatic atomization were studied,and the following work was carried out:1.Charge and electrowettability test of hybrid plant oil base coaxial electrostatic atomizationThe effects of LB2000,castor oil and a mixture of different vegetable oils(palm oil,sunflower oil,canola oil,soybean oil)as external fluid and deionized water as internal fluid were compared.The results show that using mixed vegetable oil as external fluid can optimize the charge and electrowettability.Compared with pure castor oil,the atomization current increases by 11.3%-125.9% and the electrowetting Angle decreases by4.80%-27.14% when mixed vegetable oil is used as the external fluid.2.Coaxial electrostatic atomization friction properties of mixed plant oil baseThe coaxial electrostatic atomization friction test of mixed plant oil base was carried out by using the coaxial electrostatic atomization high-speed friction device with YG8 hard alloy plate /45 steel disc as the friction pair.The friction coefficient,the wear amount of hard alloy plate and the width and depth of the grinding disc were taken as the evaluation parameters.The lubricating properties and anti-wear and anti-friction properties of LB2000,castor oil and different mixed vegetable oils as external fluids were studied.The results show that the friction coefficient of coaxial electrostatic atomization and the wear amount of cemented carbide sheet are reduced under the condition of mixed vegetable oil as external fluid,and the surface morphology of wear marks is also improved.When the mixture of soybean oil and castor oil is used as the external fluid,the optimum friction performance is obtained,and the friction coefficient and wear amount are reduced by 20.89%～96.40% and16.13%～97.33%,respectively.3.Coaxial electrostatic atomization heat transfer performance of mixed plant oil baseCoaxial electrostatic atomization test of mixed plant oil base was carried out on the experimental platform using carbide blades as heat transfer samples.The influence of mixed vegetable oil as external fluid on heat transfer coefficient and heat transfer surface state was analyzed.During the experiment,a high-speed camera was used to observe the atomization state and heat transfer surface state and analyze the cooling mechanism.The results show that the heat transfer coefficient is the highest and the heat transfer effect is the best in the nuclear boiling stage.The highest heat transfer performance can be obtained when the mixture of castor oil and palm oil 1:2 is used as the external fluid.When using castor oil and sunflower oil 1:2 or castor oil and palm oil 2:1 as the external fluid,the heat transfer effect is better than using LB2000 or pure castor oil.4.Optimization of coaxial electrostatic fog processing for mixed plant oil baseThe milling test was carried out by coaxial electrostatic atomization cutting device based on CNC milling machine.The processing comparison test was carried out first,and combined with the friction and heat transfer performance results,the optimization of mixed vegetable oil types was determined.With mixing type,mixing ratio and flow ratio as influencing factors and cutting force and cutting temperature as optimization objectives,coaxial electrostatic fog processing test of mixed vegetable oil was carried out by orthogonal experiment to optimize the values of various factors of mixed vegetable oil.The results show that the cutting force and cutting temperature can be reduced significantly in coaxial electrostatic atomization cutting by using the mixture of castor oil and sunflower oil1:2 as external fluid.The cutting force reduction range is 2%～13%,and the cutting temperature reduction range is 16%～23%.At the same time,the combination is cheaper than using LB2000 as the external fluid,and has the same or better lubrication effect.Therefore,the mixed vegetable oil can be considered as the external fluid of coaxial electrostatic atomizing cutting in practical application.