Research Of A Tool With Continuous Lubrication At The Tool-Chip Interface Based On Atomized Cutting Fluid

In this thesis,aiming at reducing the amount of cutting fluid used in the machining process and improving the anti-friction lubrication performance of the tool,the concept of continuous lubrication technology at the tool-chip interface is proposed,and a tool with continuous lubrication at the tool-chip interface is prepared.The cutting performance and anti-friction lubrication mechanism of the tool with continuous lubrication at the tool-chip interface were studied by cutting experiments.According to the technical requirements for continuous lubrication of the knife-chip interface,a special cutting fluid atomization system was designed and built,and the atomization performance tests were carried out under different cutting fluid concentrations,cutting fluid types,and system pressure parameters.It is concluded that better atomization performance can be obtained through reducing the concentration of water-based cutting fluid and promoting the pressure of the atomization system,the better the atomization performance of the atomization system.The atomization performance of this atomization system for oil-based cutting fluid is poor.Through the Abaqus software,the two-factor and three-level orthogonal simulation experiment was carried out.It is concluded that the cutting temperature increases with the augmented of the cutting speed and the amount of back engagement.The average distance between the relatively high-temperature area of the tool rake face and the main cutting edge under different cutting parameters is 0.5mm,and the average distance of the high-temperature area is 0.3mm.Using Workbench software,the indirect coupling simulation of the thermal structure of the tool was carried out,and the relevant parameters of the micro-channel were optimized and calculated by the multi-objective genetic algorithm.It is concluded that the distance between the center of the fine channel and the main cutting edge is 0.4mm,the distance with the minor cutting edge is 0.9mm,and the processing parameters of the hole diameter is 0.26 mm.The cutting performance and friction reduction and lubrication mechanism of cutting tools were compared and studied under four cutting methods: dry cutting(T-D),pouring cutting(T-W),MQL cutting(T-Q),and continuous lubrication cutting at the tool-chip interface(GT-Q).The experiment proves that when cutting 45# steel and gray cast iron,the tool GT-Q has the best cutting performance.Compared with other cutting methods,the cutting three-dimensional force,tool-chip contact length,and rake face average the coefficient of friction and the surface roughness of the workpiece are significantly reduced,and the cooling efficiency of the cutting fluid is significantly improved,but the amount of cutting fluid is only 3/25 of that of the tool T-Q.Through SEM tool surface morphology and EDS element analysis,it can be seen that the built-up edge volume on the main cutting edge of the GT-Q tool for cutting 45# steel and gray cast iron is significantly reduced,and the bonding material,micropores,and the furrows are significantly reduced,and the oxygen and iron elements only exist on the main cutting edge and the distribution is relatively sparse.At the same time,the phosphorus element distribution on the rake face is denser and more uniform than that of the tool T-Q,which proves that when cutting plastic and brittle materials,cutting the liquid has good diffusion and film-forming properties on the rake face of the tool GT-Q.However,compared with the tool for cutting 45# steel,the bonding and oxidation wear of the rake face of the tool are more serious when cutting gray cast iron,and the outlet of the micro channel of the tool GT-Q is severely blocked when cutting gray cast iron.The cutting parameters such as the concentration of cutting fluid,the pressure of the atomization system,the cutting speed,and the amount of back cutting were changed,and the cutting performance of tool GT-Q was further studied.When cutting45# steel: when the cutting fluid concentration is 10%,the cutting performance of the tool is the best,and the surface morphology of the rake face of the tool is significantly improved.As the pressure of the atomization system increases,the cutting performance of the tool also increases.As the cutting speed increases,the cutting performance of the tool decreases,and the wear increases.When the back engagement is 0.3 mm,the cutting performance of the tool is the best,and the surface morphology is improved.When cutting gray cast iron: Different from cutting 45# steel,as the concentration of cutting fluid increases,the cutting performance of the tool gradually decreases,and the wear increases.The cutting and lubricating performance of the tool will increase with the increase of the pressure of the atomization system.Different from the cutting of 45# steel,the cutting performance of the tool is improved with the increase of cutting speed,and the cutting performance of the tool is decreased with the increase of the back cutting amount.