Experimental Study On Grinding Process Of Extruding Grinding Wheel With Super Hard Abrasive

Grinding is the most widely used precision machining method.The use of superhard abrasive grinding can not only improve the stability and accuracy level of machining accuracy in specific occasions,but also expand the application range of grinding.In the field of efficient machining,there are high-speed and ultra-high speed grinding,slow feed grinding,high-efficiency deep cut grinding and other efficient grinding methods,whose material removal rate is even higher than the usual turning and milling efficiency.These new grinding processes improve the machining efficiency,but there are still many problems,such as: high temperature burn caused by grinding the surface of the workpiece to be grinded,workpiece size error caused by grinding tool wear and so on.The key to solve these problems is to control the generation of grinding heat in the grinding arc area and constrain the workpiece contour to control the distribution of surface heat flux.For this reason,the team proposed a grinding method,the grinding method of grinding with superhard abrasive wheel(abbreviated as squeeze grinding),to remove the workpiece material by using the common free abrasive squeeze grinding with the constraint of diamond revolving surface.In this paper,the method of theoretical analysis and experimental analysis is used,and the method of theoretical and experimental analysis is used to carry out a scientific and systematic research on extrusion grinding method.The specific research contents are as follows:1.Extrusion grinding method and grinding mechanismThe geometric model of extrusion grinding method is established.According to the characteristics of free abrasive grinding in extrusion grinding,the process of scratch,impact and extrusion of workpiece material by free abrasive under the constraint surface is analyzed by using the mechanical principle,and the mechanical model of free abrasive material removal under the constraint of the surface is established.On this basis,based on the stress and deformation of the material,and according to the movement track and mechanical model of the abrasive particles,the law of material chip formation is analyzed,and the theoretical model of material chip removal is established.Based on the theory of statistics,thetheoretical model of grinding area and effective number of abrasive particles is established.2.Establishment of extrusion grinding experiment platformA grinding experiment platform including self-adjusting feeder and free abrasive fluid supply cycle system was built to meet the needs of multi factor experiments and control different grinding processes.3.Preparation of free abrasive solutionA special equipment for free abrasive solution preparation was prepared,and the preparation parameters and properties of free abrasive solution were analyzed and optimized through experiments.4.Preparation of electroplate bond grinding wheelThe electroplating work station of electroplate grinding wheel was set up,and the electroplating process parameters were studied through experiments,and the electroplate metal bond super hard abrasive grinding wheel with different diamond layout schemes was prepared.5.Experimental study on material removal mechanism of extrusion grindingIn this paper,the law of material removal and chip formation in squeeze grinding is studied.The surface of the experimental workpiece and the debris are observed and measured by means of ultra depth of field microscope,roughness measuring instrument and other instruments.The observation shows that the surface of squeeze grinding has the shape of free abrasive extrusion,and the debris presents the shape of particles,which proves that the surface and the formation law of abrasive are in accordance with the established theoretical model of squeeze grinding.6.Experimental research on basic process lawExperiments were carried out on the main technological factors affecting the grinding effect,and the basic rules of extrusion grinding technology were obtained: the grinding surface roughness increases with the increase of free abrasive fluid concentration;the larger the free abrasive particle diameter is,the higher the surface roughness value is;the feed speed mainly affects the grinding clearance,and the optimal grinding surface is obtained when the clearance and free abrasive particle size are approximate;the grinding wheel extrusion grinding The increase of grinding speed will increase grinding efficiency,but reduce surfaceroughness;the increase of radial cutting depth can improve grinding efficiency,but the excessive cutting depth will increase grinding temperature,so it is necessary to reduce the working speed or increase the grinding speed of the grinding wheel to avoid the damage of grinding caused by the longer free abrasive action time and temperature rise;grinding wheel The denser the arrangement of wheel diamond,the better the grinding effect.